Although the cathedral dates from the 15th century, its brilliant ceiling and gleaming stained-glass windows are the result of 19th-century restoration by architect Sir Gilbert Scott. Don't miss the memorial near the altar to an event in 1214, when the barons of England took an oath here to force King John to grant the Magna Carta. The cathedral's original Abbey Gate was destroyed in a riot, and it was rebuilt in the 14th century with defense in mind—you can see the arrow slits. From Easter to September, guided tours are available Monday to Saturday at 11:30. There's also a small but popular café.