Part of our Green Healing in Ealing series, this story follows a community-led adventure into Horsenden Hill during the City Nature Challenge—where curiosity met conservation, and neighbours became nature scientists for the day.
London Locals. Global Challenge. Real Impact.
Less than two weeks ago, a small but passionate group gathered at Horsenden Hill to take part in the City Nature Challenge (CNC) — a global wildlife survey that turns everyday people into community scientists. The event brought together nature lovers, curious locals, and environmental professionals, thanks to an inspiring collaboration between Regen City (host), The Green Londoner, Wildya, and Go Jauntly.
The meeting point? Horsenden Farm — an idyllic haven tucked away in the Horsenden Hill Nature Reserve.
If you’ve never ventured out to Horsenden Hill, it’s a hidden oasis in West London (Ealing) where the noise of the city fades and leafy trails invite you to slow down and reconnect with nature. With gnarled trees over a hundred years old, wildflower meadows bursting with life, and birdsong in the air, it feels like a world away. From the hilltop, panoramic views stretch across London — a striking reminder of the delicate balance between urban life and the natural world.
What Is the City Nature Challenge?
The CNC is a global, four-day bioblitz that invites people to step outside, explore their local surroundings, and help scientists document urban wildlife. All you need is a smartphone and a sense of curiosity!
Each year, cities across the world take part in this friendly competition to see who can log the most observations and identify the highest number of species. In 2024, more than 83,000 participants submitted over 2.4 million observations, recording 65,000+ species globally.
For the 2025 edition, over 400 cities — including London — were invited to take part from 25–28 April. The challenge unfolded in two parts:
📸 April 25–28: Observe and photograph wild plants, fungi, and animals.
🔍 April 29–May 4: Help identify and verify the species online.
The results, announced on 5 May, showed London held its own with:
- 19,127 observations
- 1,883 species recorded
- 602 participants
Our group may have been small — but definitely competitive!
A Day of Discovery
The day began with warm introductions as attendees shared why they’d joined—from seasoned ecologists to first-time wildlife spotters. The Green Londoner’s founder, Gautier Houel, opened with a few words on the power of community-led science and reconnecting with nature.
Participants then split into two groups for a guided nature walk. Armed with the iNaturalist app, they explored the trails, snapping photos of plants, insects, birds, and fungi. Each upload contributed real-time data to the global CNC—a hands-on way to support biodiversity research right from their own neighbourhood.
As they wandered the winding paths of Horsenden Hill, the groups spotted parakeets, bumblebees, and butterflies darting between the trees. Around every corner, there was something new to discover: a peaceful field of sleepy cows, a towering tree inviting both adults and children to climb, and a hilltop clearing with sweeping views of the city beyond. One group even lifted a heavy tree stump to reveal a hidden world of slugs and snails tucked beneath. Curiosity echoed through the woods, as naturalists shared tips on identifying tree species and spotting signs of disease in leaves.
After 90 minutes of walking, photographing, and learning, everyone reconvened at Perivale Brewery—a rustic local gem. Under the spring sunshine, pizzas were shared, drinks poured, and favourite finds exchanged. There was a real sense of joy and pride in having contributed to a global science effort, right from their own patch of London.
Why It Matters
Nature is all around us—even in cities—but much of it goes unnoticed. Events like the City Nature Challenge help shine a light on urban biodiversity, foster community connection, and support scientists tracking how ecosystems are evolving.
More than just a walk through the woods, this event reminded us that reconnecting with nature can be meaningful, collaborative, and deeply rewarding.
To learn more:
🌍 City Nature Challenge: https://citynaturechallenge.org
🌿 Horsenden Farm: https://horsenden.org/
Written by Mia Alberro, a storyteller passionate about how human behaviour shapes — and is shaped by — the climate crisis. Born in Venezuela, raised in New Jersey, and now based in London, she explores local stories with a global lens.
