Despite its building density and growing population, London is one of the world's greenest cities. The centre is home to eight Royal Parks, including Green Park and St James' Park which surround Buckingham Palace, along with the more westerly Hyde Park and Kensington Gardens. There are also council-funded parks, like Crystal Palace, which is home to a ‘Dinosaur Court' as well as a maze and athletics centre. Rent a car from London Gatwick Airport and visit the Royal Botanic Gardens in Richmond, 50 minutes away. Here you can explore the ‘Treetop Walkway', see the 17th-century formal garden and see the stunning Kew Palace.