London’s Biodiversity Hotspots

Central London isn’t all glass and concrete. Scattered among the offices and historic landmarks are pockets of green teeming with life

These Sites of Importance for Nature Conservation (SINC) range from tiny churchyard gardens to larger squares. They are classified by their significance as Metropolitan (London-wide), Borough Grade 1 or 2 (borough-wide importance), or Local (neighbourhood value). 

Below we explore key SINCs in central boroughs – with a focus on the City of London – highlighting what makes each special, which rare species call them home, and whether you can visit.

City of London: Wildlife in the Square Mile

The City of London (“Square Mile”) is intensely built up, yet it hosts several green oases. The City of London Biodiversity Action Plan (2021–2026) notes that the area’s green spaces are “small [and] fragmented” amid dense development.

Many serve multiple human needs, limiting their wildness. The City’s strategy is to boost the biodiversity value of these sites and link them via new green infrastructure. Despite their size, these spots are vital refuges for urban wildlife.

The River Thames (and its tidal channels) – Forming the City’s southern boundary, the Thames is designated a Metropolitan SINC. This tidal river is a major wildlife corridor through London, with tidal mudflats that feed wading birds and marine life.

Even in the heart of the financial district, you might spot cormorants drying their wings or seals and porpoises swimming by. The river connects habitats across boroughs, illustrating why a map of central London’s SINCs would show the Thames as a blue-green ribbon linking many sites.

The Temple Gardens – A series of historic gardens in the Inner and Middle Temple (Inns of Court) on the City’s western edge. Temple Gardens are rated of Borough Importance (Grade 2) and feature lawns, mature plane trees, and flower beds set among barristers’ chambers. They provide habitat for birds and pollinating insects along the Thames embankment.

Though privately managed, the main Inner Temple Garden welcomes the public on weekday lunchtimes (approximately 12:30–3pm). At those times, anyone can stroll under its ancient trees and admire seasonal plantings – a rare chance to enjoy this Grade II listed garden. (Middle Temple’s gardens are usually closed except on special open days.) The limited hours mean wildlife faces little disturbance, while office workers get a peaceful break in nature.

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Postman’s Park – Tucked behind St Paul’s Cathedral, Postman’s Park is a Site of Local Importance that is open to all. This small garden, shaded by towering London plane trees, is famed for its Memorial to Heroic Self-Sacrifice. It’s also a quiet ecological haven amid busy streets. Lush flower beds and a small pond support pollinators and birds.

Improvements in planting have been made to bolster its status as a SINC. You might see butterflies flitting among the blooms or a robin hopping near the benches. The park’s mix of sun and shade plants offers resources for insects like bees, even in a tiny urban plot. And since it’s a public park (free entry during daylight hours), it’s a favourite lunchtime spot for nearby office staff seeking a bit of greenery.

St Dunstan-in-the-East Church Garden – One of the City’s most striking secret gardens, set in the ruins of an old Christopher Wren church. Bombed in WWII, the roofless nave is now open to the sky and dripping with greenery. Curtains of ivy and fern cling to gothic arches, demonstrating the “masonry habitat” that old walls can provide for plants and invertebrates. Palm trees and buddleia grow where pews once stood. This garden is slated for Local SINC designation and is freely accessible to the public.

Despite being steps from the Monument and the Tower, it feels serene – often city workers sit on benches here to eat lunch or read, accompanied by pigeons and the sound of a central fountain. The combination of sheltered walls and diverse plant life shelters small birds and pollinating insects in an otherwise concrete-dominated area.

Barbican Wildlife Gardens – The Barbican Estate includes several interconnected green areas like the Barbican Wildlife Garden, St. Alphage’s Garden, and the Barber-Surgeons’ Garden (with its famed wildflower meadow). Together these have been proposed as an upgraded Borough Grade 1 SINC . They feature lawns, ornamental shrubs, and even a pond that attracts dragonflies. The Barbican’s mix of private residential gardens and semi-public podium plantings provides habitat for house sparrows, a species that has vanished from many parts of London but still clings on here.

Access is partially restricted (some areas for residents or open on special events), but the public can view St. Alphage’s Garden (a small raised garden by London Wall) and peek into Barber-Surgeons’ Garden on open days. These gardens’ location by remnants of the old City Wall again highlights how historic structures become wildlife niches – ferns and lichens sprout in cracks of the Roman Wall at Noble Street.

In fact, the City is recognizing the “Roman Wall, Noble Street and St Anne & St Agnes Churchyard” as a new combined SINC site. Here, old stonework plus planned pollinator-friendly plantings create a surprising urban meadow amid office blocks.

Historic Churchyard Gardens – Scattered through the City are small churchyards turned pocket parks. St Paul’s Cathedral Garden (Local SINC) rings the famous dome with lawns and shrubbery, offering both tourists and wildlife a breather. St Botolph without Bishopsgate Churchyard (near Liverpool Street) and St Olave Hart Street Churchyard (Pepys’ graveyard near Fenchurch Street) are also Local SINCs now managed as gardens with flower borders, trees, and seating.

They may be small, but such churchyards are known to host a diversity of life – “woodland edge species such as bats, stag beetles, spotted flycatchers, tawny owls and song thrush” have all been recorded in London’s churchyards. In the City, you are unlikely to see a tawny owl, but bats (Common pipistrelles) do forage on insects at dusk around lit church spires.

And while the stag beetle (a large endangered beetle) is more common in suburban south London, decaying wood left in City churchyard corners could one day attract them – the City’s BAP even chose the stag beetle as a flagship species to encourage creation of log piles and deadwood habitat. The stone tombs and walls also nurture mosses, lichens, and ferns, adding to urban biodiversity. These churchyard parks are free and open in daytime, functioning as “open air sitting rooms” for Londoners and habitats for nature at the same time.

Notable Species

The City’s crowded skyline hides some remarkable wildlife. The Biodiversity Action Plan identifies target species that symbolize the City’s urban nature, including the black redstart and peregrine falcon. The Black Redstart – a little grey bird with a fiery tail – famously colonized Blitz rubble sites and now nests on City rooftops and ledges.

Astonishingly, the City of London may host at least 10% of the UK’s breeding population of Black Redstarts, a “significant” portion that makes this area crucial for the species . Any new development in the Square Mile must therefore consider rooftop habitat or risk harming this rare bird. Green roofs with a mix of sedums, wildflowers, and gravel are encouraged, doubling as both rainwater SuDS and bird habitat.

Meanwhile, Peregrine Falcons – once endangered – have adapted to hunt pigeons above the streets; a pair nests on a high-rise tower in the City (they have used sites like the Barbican towers in past years). At ground level, pollinators benefit from each flower bed and pocket of greenery. The City actively promotes planting for pollinators: for example, wildflower terraces in places like Cleary Garden (a terraced wine-themed garden and Local SINC) attract bees and butterflies.

Across the Square Mile there are also wild bee hotels and nectar-rich planters. The London Wildcare Trust notes that bee populations have been declining due to habitat loss, so creating urban “bee gardens” and installing bee hotels helps support these crucial pollinators. Thanks to such efforts, even tiny sites can host buzzy communities – from bumblebees on lavender to solitary mining bees burrowing in odd corners of lawns.

In summary, the City of London’s SINCs – whether a riverside garden or a church crypt yard – form a network of micro-habitats. The Square Mile’s green sites are like pollinator stepping stones amid the office blocks.

The City’s goal is to improve connections between them (for instance, encouraging developers to include green roofs and terrace gardens to link ground-level sites). These mini-wild spaces are not just decoration; they are key to “bringing nature into the City” and sustaining the birds, insects, and other species that have adapted to urban life.

City of Westminster: Small Sanctuaries in a Big City

Westminster has some of London’s most famous parks (Hyde Park, Green Park, Regent’s Park) which are of Metropolitan Importance. But alongside these grand parks are lesser-known sites of borough and local importance for nature. Many lie hidden in squares or around historic buildings, providing important habitat in central London’s West End.

St John’s Wood Church Grounds – In the northwest of the borough (near Lord’s Cricket Ground), this site is Grade 1 Borough Importance and is Westminster’s only Local Nature Reserve . Formerly a 19th-century graveyard, it now blends formal gardens with a wild “nature area.” There are hedges, a wildflower meadow and a patch of woodland among the old gravestones.

This mosaic makes it “a good site for butterflies” and birds. Indeed, visitors have recorded speckled wood butterflies dancing in the dappled shade and stag beetles have been reported in summer months taking advantage of the abundant dead wood. At dusk, pipistrelle bats swoop in the churchyard catching insects. The site is open as a public park and includes a playground, serving both nature and the community. Its Green Flag Award attests to its value as a well-managed green space.

Here you can sense what many central London churchyards might once have been like – a peaceful, semi-wild haven, surprisingly “rural” in feel. The success of St John’s Wood Church Grounds shows how even a small inner-city woodland patch can support notable biodiversity (from bats to butterflies) when managed with wildlife in mind.

Westminster Abbey Gardens and the Temple Church – Around Westminster Abbey, small private gardens (like the College Garden and the Abbey Orchard) harbor old trees and medicinal plants, though public access is limited. Similarly, the Temple Church’s precinct straddles the City/Westminster boundary; its gardens (covered under City’s Temple SINC) illustrate cross-borough habitat.

These spaces, while not generally open to the public daily, contribute to biodiversity by offering undisturbed refuge. Ancient lime and fig trees at Westminster Abbey, for example, support nesting blackbirds and colonies of hoverflies. During occasional open days, visitors might spot honeybees from the Abbey’s own hives pollinating the lavender borders.

Such semi-restricted sites remind us that not every green haven is visible or accessible – but they still matter ecologically. (Many of Westminster’s residential garden squares similarly are gated private spaces that act as quiet mini-woodlands for wildlife, even if only accessible to keyholders.)

Other Notable Westminster SINCs – In central Westminster, formal garden squares and churchyards provide pockets of nature. Embankment Gardens along the Thames have ornamental flower beds that feed city bees and butterflies. Victoria Embankment Gardens and Temple Gardens (the western portion lies in Westminster) together create a corridor of greenery by the river. In the heart of Soho and Covent Garden, where green space is scarce, community gardens are vital.

For instance, The Phoenix Garden in St Giles (just over the borough border in Camden) is a celebrated community-run Local SINC . It’s a “green oasis within a densely built up area” filled with native wildflowers and even a pond. Such features attract pollinators and birds – Phoenix Garden’s plantings of bluebells, ox-eye daisies, water mint and more have turned a former bombsite into habitat for tits, finches, newts and dragonflies.

This garden is open to all at no charge, offering a peaceful retreat from nearby traffic and a hands-on example of urban biodiversity. Corporate volunteers often help here, seeing first-hand how wildflower planting in the city centre boosts insect life. Back in Westminster, similar small-scale sanctuaries include Golden Square in Soho (with its mature trees hosting night-time bat visits) and St. James’s Church Garden on Piccadilly, where a mix of ornamental and wild planting draws butterflies right on a busy shopping street.

Westminster’s approach has been to identify these little sites and protect them in local planning. The payoff is a network of stepping-stone habitats: a butterfly can travel from a window-box to Soho Square to Green Park; a house sparrow population in one private square can disperse to another if there are green links. A borough-wide map of SINCs would show Westminster’s large parks encircled by these smaller sites, all collectively keeping the city alive with birdsong and blooms.

Camden and Islington: Green Gems on the Northern Fringe

Just north of the City and Westminster, the boroughs of Camden and Islington form part of central London’s biodiverse patchwork. These areas contain important squares, gardens and canals that function as ecological corridors.

Bunhill Fields (Islington) – An example of a historic cemetery now managed for nature. Bunhill Fields, a Nonconformist burial ground just north of Moorgate, is owned by the City of London but lies in Islington. It is designated a Grade II Borough SINC and is open to the public as a park. With about 1.6 hectares of green space and around 130 mature trees (plane, lime, horse chestnut) shading its lawns , it creates an “open woodland” environment in the city. The damp, shaded conditions plus centuries-old gravestones lead to a “lush growth of mosses and lichens” on stone surfaces.

Several unusual moss species have been recorded here, indicating clean air pockets. Birds thrive in Bunhill’s quiet canopy: chirping great tits, blue tits, wrens and robins are common . In fact, a pair of spotted flycatchers (a declining woodland bird) even bred here a few years ago – an astonishing find for central London.

At lunchtime, office workers from the Old Street tech district file in with sandwiches; it’s “a popular leafy retreat for lunchtime picnickers from local offices”. These daily visitors may not realize they’re sitting amid rich biodiversity.

But if you watch, you’ll notice butterflies visiting wildflowers left in the grass, or hear the high-pitched calls of bats that come out on summer nights. Bunhill Fields shows how conserving an old graveyard’s wild character – mowing grass less often, retaining dead wood and big trees – can support everything from insects to birds in the urban core.

Bloomsbury and Kings Cross Squares (Camden) – Camden’s southern end, around Bloomsbury, Holborn and King’s Cross, contains a string of garden squares that double as wildlife habitats. Russell Square, Bloomsbury Square, and Lincoln’s Inn Fields all have lawns and tall plane trees that provide roosts for birds (and in summer, feeding for migratory swifts that screech overhead catching insects).

While these formal squares are not “wild” in appearance, some are recognized as Local SINCs by Camden for their mature trees and birdlife. Gray’s Inn Gardens (the “Walks”) is a private green space (open to the public at limited times) with ancient trees and a rookery of crows – a rare sight in zone 1. At King’s Cross, the Regent’s Canal cuts across Camden, serving as a blue-green corridor. Towpath vegetation and canal basins (like Battlebridge Basin near Camley Street) host aquatic plants, fish, and waterfowl right next to bustling Granary Square.

The Camley Street Natural Park is a notable 0.8 ha nature reserve by the canal – though just outside our “corporate central” focus, it exemplifies how even former coal yard land can be rewilded into ponds, reedbeds and woods frequented by reed buntings and amphibians. Together, Camden’s pockets of nature interlink: a bird or butterfly can hop from Regent’s Park (northwest Camden) down the canal and through these squares towards the Thames.

Community Gardens and Pocket Parks – Both Camden and Islington have many community-led gardens that fill gaps between buildings with greenery. We mentioned The Phoenix Garden in St Giles (Camden) as a thriving Local SINC . In Islington, similarly, the Culpeper Community Garden in Angel and the King’s Cross Skip Garden (a movable garden project) have brought pollinator-friendly planting into dense urban zones.

These are usually open to the public and often feature diversity in planting (herbs, wildflowers, ponds) that attracts bees, butterflies, and even newts. They also engage local workers and residents in gardening, fostering stewardship of biodiversity. Such gardens, while tiny (often under 0.2 hectares), collectively contribute to what one might call “urban ecological corridors.”

For example, bees might travel from one green roof or community plot to the next, never realizing the cityscape in between. This highlights an important point: the distribution of many small sites can be as crucial as the size of a single site. London’s biodiversity value lies in this mosaic of big and small green areas woven through the city.

South of the River: Linking the Green Chain

Central London’s south bank (in Southwark and Lambeth) mirrors these trends. While not detailed in our main sources, it’s worth noting that just across the Thames, you’ll find sites like Red Cross Garden in Southwark – a restored Victorian garden with a pond and cottage plantings, providing a “secret sanctuary” near The Shard.

Southwark Cathedral’s churchyard, local parks like Mint Street Park and community gardens managed by Bankside Open Spaces Trust all contribute to biodiversity in SE1. The Thames itself unifies north and south: its banks in Southwark are part of the same Metropolitan SINC as in the City.

Black redstarts famously nested for years on the Southwark side at the Tate Modern’s roof, and peregrine falcons have a long-running nest on the former Bankside Power Station – reinforcing how wildlife doesn’t heed borough boundaries. Green roofs and terraces on newer developments (like the Blue Fin building on Southwark Street, which has wildflower roofs) are creating aerial green links. Lambeth, too, has central gems like the Archbishop’s Park and Waterloo Millennium Green that host wildflower meadows for pollinators in the shadow of the London Eye.

A map of central London’s ecological network would show the Thames crossing through and species moving north-south as well as east-west. For instance, bats commute along the river corridor, and birds such as wagtails and kingfishers follow the water into the urban core. Recognizing this, the Mayor’s London Environment Strategy emphasizes enhancing these corridors so wildlife can disperse and populations remain resilient.

Access and Engagement

An important aspect of these SINCs is whether they are open to the public or restricted:

Open to Public: Parks and gardens like Postman’s Park, St Dunstan-in-the-East, Bunhill Fields, Phoenix Garden, St John’s Wood Church Grounds, and most churchyard gardens are freely accessible. They invite daily engagement – office workers eat lunch, tourists wander, locals relax – and in doing so, people experience biodiversity up close. This builds support for conserving such sites.

For example, Bunhill Fields and St John’s Wood Church Grounds regularly host guided walks for the public, highlighting bats or birds present. Community gardens often have volunteer days where anyone can help maintain the space and learn about urban wildlife.

Limited/Restricted Access: Some of the most biodiverse spots are semi-private. Inner Temple Garden is open only on weekday middays ; many private squares in Bloomsbury or Westminster are behind locked gates (accessible to residents or during Open Garden events). Barber-Surgeons’ Garden in the City is usually closed except by arrangement. While these sites still benefit biodiversity, lack of public access means fewer people directly appreciate them. It places greater onus on the owners to manage wisely for nature.

Encouragingly, several institutions do open up occasionally (e.g., Open Garden Squares Weekend in June allows access to many normally closed gardens). Corporate campuses in London are also joining in – some office developments now feature accessible roof gardens or ground-level pocket parks that function as SINCs and are open to both employees and the public (for instance, the Nomura Bank’s roof garden or the public garden at 120 Fenchurch Street). Such models blur the line between private and public green space for the benefit of all.

The Bigger Picture

Even in the heart of London, nature survives and in many cases thrives, given half a chance. However, it faces constant pressure. According to one urban wildlife group, even major green spaces like Hampstead Heath and Epping Forest (just outside the center) are being increasingly “fragmented and degraded” by development . This makes the network of small central sites even more critical.

They act as refuges and stepping stones, allowing species to move through the city’s landscape. A butterfly or a bee doesn’t need Hyde Park if it can find a chain of pocket gardens with flowers; a sparrowhawk hunting pigeons may rest in a quiet churchyard tree on its way across town.

London’s ecological network plan identifies strategic corridors and green chains that connect these SINCs. Central London’s contribution comes from linking the Thames corridor to the royal parks to the smaller sites. There is an opportunity for businesses and local authorities to further enhance connectivity – for example, installing green roofs on office buildings to connect with nearby parks, or planting street trees between sites to create continuous canopy.

Finally, protecting these central SINCs is not just about wildlife – it’s about people too. These green enclaves provide city dwellers and workers with cleaner air, cooler temperatures in summer, and a proven boost to mental well-being. Many are literally “open-air sitting rooms for the tired inhabitants” of the city , fulfilling a vision from over a century ago when philanthropist Octavia Hill created Red Cross Garden as a place for both rest and nature. Today, corporate professionals in London can become champions of urban biodiversity by simply using and appreciating these spaces.

Whether it’s enjoying the sight of a bold black redstart atop an office block or supporting a local garden volunteer group, engagement is key. In plain terms: look after these small wild places, and they will look after us – by enriching our urban experience, sustaining iconic species, and keeping London a living, breathing city.