Royal London

A 1,000-year-old fortress founded by William the Conqueror in 1066 after his Norman invasion. It has served as a royal palace, prison, execution site, armory, treasury, and zoo. Anne Boleyn was beheaded here in 1536 on Henry VIII's orders. The Crown Jewels — including the 530-carat Great Star of Africa diamond — have been kept here since 1661. Six ravens are always maintained on the grounds; legend says if they leave, the kingdom will fall. The Yeoman Warders (Beefeaters) have guarded the tower since 1485.

The best view of Tower Bridge is from the riverside walkway just east of the Tower. The White Tower, the oldest part, houses a stunning collection of royal armor.

Often mistakenly called London Bridge, this Victorian Gothic bascule bridge was built between 1886 and 1894 to ease traffic while still allowing tall ships to reach the Pool of London. The two 65-meter towers are connected by high-level walkways with glass floors added in 2014. The bridge still lifts about 800 times a year — schedules are posted online. The steam-driven hydraulic system that originally powered it is now a museum in the south tower. Engineer Horace Jones died during construction and never saw it completed.

The glass floor walkway 42 meters above the Thames offers vertigo-inducing views of boats passing below. Check the lift schedule online to watch the bridge open.