Hollow Ponds, also known as Leyton Flats is a part of Epping Forest that forms the northern border of Leytonstone with Snaresbrook.
Sitting at the top of the Lea Valley, it is one of the few places in London where you can stand and look up to the sky and, with the exception of one block of flats, no buildings are higher than the tree line.
Rowing boats are available for hire, teas, coffees, ice creams and snacks are available from the boathouse, Lakeside Diner and Log Cabin and the Sir Alfred Hitchcock Hotel on Whipps Cross Road has commanding views over the forest.
There was once an open-air swimming pool by Hollow Ponds (Whipps Cross Lido) which was originally dug as part of an unemployment project in 1905, became a modern swimming pool in 1932 but was closed in 1982 due to ongoing problems with water quality and vandalism. There are some interesting websites with memories and pictures of the Lido:
Whipps Cross/Hollow Ponds area map