London has a number of open spaces scattered throughout the city. The largest of these in the central area are the Royal Parks of Hyde Park and its neighbour Kensington Gardens at the western edge of central London, and Regent's Park on the northern edge. More central are the smaller Royal Parks of Green Park and St. James's Park. Hyde Park in particular is popular for sports and sometimes hosts open-air concerts. A number of large parks outside the city centre are also notable, including the remaining Royal Parks of Greenwich Park to the south east, and Bushy Park and Richmond Park to the south west. Some more informal, semi-natural open spaces also exist, including the 791-acre Hampstead Heath of north London.