Three notable outdoor bathing ponds can be found on the heath, each offering a unique experience. The Men's Pond and Women's Pond are located along the eastern edge, part of a series of small lakes known as Highgate Ponds. On the opposite side lies the Mixed Pond, which is part of Hampstead Ponds.
When planning a visit, it's important to note that swimming hours at these ponds are seasonal and can change frequently. They also vary based on age groups, so checking the schedule beforehand is recommended to ensure access during desired times.
Source - https://en.wikipedia.org/wiki/Hampstead_Heath_Ponds