Hyde Park is central London's largest green space, expropriated from the church in 1536 by Henry VIII and turned into a hunting ground and later a venue for duels, executions and horse racing. The 1851 Great Exhibition was held here, and during WWII the park became an enormous potato field. These days, it's a place to stroll and picnic, boat on the Serpentine lake, or catch a summer concert or outdoor film during the warmer months.
Plonk into a deckchair (one hour/all day £1.80/9) with a chunky novel between March and October.
Between November and early January, the southeast area of the park is the site of Winter Wonderland, with fairground rides, ice skating and other seasonal attractions.
While Speakers' Corner in the park's northeast corner is intended for oratorical acrobats, these days it's largely eccentrics and religious fanatics who address bemused onlookers, maintaining a tradition begun in 1872 as a response to rioting. Nearby Marble Arch, designed by John Nash in 1828 as the entrance to Buckingham Palace, was moved here in 1851. It replaced the infamous Tyburn Tree, a three-legged gallows that was the place of execution for up to 50,000 people between 1196 and 1783.