The Welsh Harp is an oasis in London and one of the best places to see wildlife, especially wetland birds. It's very much off the beaten track and a great space for escaping the city. Surrounding the reservoir are woodlands, meadows and hidden areas to explore, some require quite a bit of intrepidness! Unfortunately, a complete circuit isn't possible without using roads, but all sides offer something different and it's well worth making the effort. In winter it can be very muddy in places, otherwise it is reasonably accessible, best paths from the Birchen Grove car park. The site also has a fascinating history, built to feed the canals, it was very much a pleasure ground in the late 19th Century, was used by Naturists in the 1920s until a riot broke out, it has hosted Olympic water sports and it was used in both World Wars.