Hampstead Heath, London

Hampstead Heath is a public open space, but its ponds reveal a surprisingly engineered past. Along the heath’s edges, around thirty ponds occupy hollows shaped by human hands. Many began as reservoirs in the seventeenth and eighteenth centuries, supplied by springs at the head of the River Fleet.

The Highgate chain emerged after the Hampstead Water Company dammed a brook in 1777. Look toward the bathing ponds: three remain available for open-water swimming, with separate facilities for men and women and another for mixed bathing. Their survival followed a legal fight.

When the City of London Corporation sought to close them in 2004, swimmers challenged the decision in the High Court and won. A mound near the men’s pond carries a different story: as local legend has it, Queen Boudicca lies buried there, though historic images show a seventeenth-century windmill on the spot.