The Serpentine is a long, thin artificial lake located within Hyde Park. This charming water body is home to a variety of waterfowl and fish. Originally, the lake came to life by damming the River Westbourne, but today, it is nourished by three boreholes. Interestingly, the western part of the lake extends into Kensington Gardens, where it is known as The Long Water.
Visitors to the Serpentine can enjoy a range of activities. Swimming and boating are particularly popular pastimes here, providing a refreshing way to experience the serenity of the lake. Whether it's a leisurely boat ride or a brisk swim, there's something for everyone to enjoy amidst the tranquil waters.
Source - https://en.wikipedia.org/wiki/The_Serpentine