Hampstead Heath is a large, ancient London heath, covering 320 hectares. This grassy public space sits astride a sandy ridge, one of the highest points in London, running from Hampstead to Highgate, which rests on a band of London Clay. The heath is rambling and hilly, embracing ponds, recent and ancient woodlands, a lido, playgrounds, and a training track, and it adjoins the former stately home of Kenwood House and its estate. The south-east part of the heath is Parliament Hill, from which the view over London is protected by law.
Running along its eastern perimeter are a chain of ponds – including three open-air public swimming pools – which were originally reservoirs for drinking water from the River Fleet. The heath is a Site of Metropolitan Importance for Nature Conservation, and part of Kenwood is a Site of Special Scientific Interest.