This section of the novel is set at the men-only swimming pond on Hampstead Heath.
On the Heath, there are about thirty ponds which were dug originally as reservoirs in the 17th and 18th centuries. Three of these, known as Hampstead Ponds, or Highgate Ponds, are used for swimming. Of the three bathing ponds, one is exclusively for men, one exclusively for women, and one is for mixed bathing.
The Men's Pond, like Hampstead Heath in general, is a popular venue for gay men.