Bromley is the largest of the London boroughs and promotes itself as the clean and green borough. Bromley plays host every year to the Biggin Hill Air Fair held in June at Biggin Hill Airport, an important airfield during the Battle of Britain. Bromley is home to Crystal Palace Park boasting London's largest maze, as well as Crystal Palace Bowl. The latter is the venue for many summer concerts, including the Bank Holiday firework spectacular held in August and the Best of Last Night of the Proms.
Other attractions include Chislehurst Caves with its remains of chalk mines said to date back to Roman times. The newly opened Darwin Museum allows visitors to view original manuscripts and belongings of the world-famous naturalist, Charles Darwin.