The focal point of the park is definitely The Serpentine. This eighteenth-century lake with an elongated shape hosts the Peter Pan Cup every Christmas: a swimming contest for...those who never grow up, where you can watch sixty-six contestants who, besides challenging each other, are also challenged by the cold and their age. But compared to the past, today the waters of The Serpentine are much cleaner since the lake's intense restoration for the 2012 Olympics, when it hosted the open-water swimming races.
You can find restaurants and bars near The Serpentine in addition to the long fountain built in honour of Princess Diana and inaugurated by Queen Elizabeth as a sign of reconciliation between the royal family and the memory of the tragic princess.
To the north, The Serpentine narrows into the basin called The Long Water. At one end there's a beautiful sculpture by Henry Moore, while not far from the north tip you can visit the pet cemetery inaugurated in 1880 with the Duchess of Cambridge's sighthound.