The October sky is bright, with a glowing film of city vapour. I live in a smoke-filled bubble, encircled by the M25. It’s a wonder anything survives here, let alone a nature junkie like me.

I push my way past Caribbean hairdressers and food-and-wine shops to a spot around the corner that’s usually good for what ails me. The woods nearest (and dearest) to me are on a steep hill – though the view from the top makes up for the muddy climb.

As the tarmac underfoot turns to earth I breathe a sigh of relief. The silence seems overwhelming. Just seconds ago I was in a concrete jungle, but now I stand surrounded by damp earth, wood and October’s sepia tones. I’m still in an urban bubble, but the air here seems clearer somehow.

Summer’s warmth has long since left the wood and I’m beginning to wish I’d brought my coat. Fallen leaves crunch satisfyingly underfoot like breakfast cereal. I head into the undergrowth, the tang of leaf mould on my tongue. This secret woodland is always deserted. On an old wooden post an arrow points right, although I’m not sure what it’s directing me to. As far as I can tell I’m lost in the wild, just as I want to be.

With a screeching ‘ki-ki-ki’, I’m no longer alone. The trees shake as dozens of neon-green parakeets sound their alarms. Cover blown, I stand and wait as the frenzy of beating wings quietens down to a simmer. This is their turf, and I’m an intruder. These woods, like many others in London, are home to rose-ringed parakeets (Psittacula krameri), and it feels as though this is their stronghold, the place they return to once all the cherry trees and bird feeders in the nearby gardens have been stripped bare. It’s hard not to love these garish invaders with their clown-like beaks and bold personalities. As I turn to walk away from their circus, one pops its head out of a hole to look at me with perfect comic timing.

I take a detour via one of the wood’s barely used tracks. A speck shoots past me into the bracken: firecrest! The flash of orange on its forehead is the only way of telling it apart from its cousin, the goldcrest. These autumn featherweights are a highlight of the season. Due to their camouflage of yellow and orange, spotting one seems less likely than finding a needle in the proverbial haystack. Britain’s smallest bird is not, however, lacking in character – and likes to make itself known. Spending most of their time upside down as they flit from branch to branch, they are nature’s trapeze artists.

At the top of the wood, in a clearing, stands one of South London’s iconic antennae. For something so massive and unnatural to be in the woodland feels jarring, but the birds don’t mind it at all; in fact several parakeets perch on its frame to enjoy the same view for which I’ve traipsed through mud and dead leaves.

Having reached this vantage point I choose the least woodlouse-riddled log I can find and sit for a while. I love these city woods. Most are low-lying, with views no more than fifty feet in front, but here I can see for miles. Evergreens stick out through the mosaic of coppery deciduous foliage and brown earth. This is where the change in seasons can be best appreciated.

When I think of the woods, I think of autumn, for woods are nature’s calendar. No other landscape is transformed so totally, and none more dramatically than by the annual autumn gilding. With the sepia tones comes an almost overwhelming sense of nostalgia. I’m cast back to my childhood, building dens and collecting pine cones. I was brought up a nature junkie – and I’ve found my fix, here in the heart of the city.

Will Harper-Penrose, 2016