It's designated as a Site of Special Scientific Interest and a National Nature Reserve that's home to birds, butterflies and animals including herds of deer. You can just about make out the shape of a doe between the trees in the picture on the right. You aren't supposed to get too close to the deer as they're wild animals, and autumn is the rutting season.
For those who like ancient sacred sites, the park contains a Bronze Age burial chamber, now called King Henry’s Mound because legend has it King Henry VIII used it as a viewing point when out hunting. If you stand on it you can see panoramic views of the Thames Valley to the west and a protected view of St Paul's Cathedral to the east. Lee Edwards took a photo of it for this blog a couple of years ago and you can see that post here.
I've been blogging regularly about London's green spaces in an effort to dispel a prevalent myth in the pagan community that it's just all concrete. My posts cover everything from beautiful trees in the Square Mile itself, to gardens in and around Bloomsbury, to rivers running through meadows in south London, to large parks and woods where you can wander for hours.
Some previous Green London posts: