London's largest park is where the city's inhabitants come to relax and enjoy the sunny days. It is also one of the eight Royal Parks in London.
During the 2012 Summer Olympics, the Triathlon took place here. There are various events (e.g. Royal Gun Salutes) organized here all the time. Be sure to check the calendar on the official website before your visit.
There are several memorials located in the park, one of the most imposing ones being Diana Memorial Fountain (commemorating Diana, Princess of Wales and her tragic death).
Many sites are also located in the park including the Speakers' Corner, an area for open-air public speaking and discussion.
Daily: 5 am - midnight
Admission is free.