The oldest church in the City, All Hallows has been a place of worship since 675 CE. It was spared in the Great Fire, but much of today's building is from the 1957 post-Blitz reconstruction, though the bombing did uncover a Saxon-era arch. The museum in the crypt has a number of curious artefacts, including a slab of 2nd-century tessellated Roman pavement and a historic church register documenting the marriage of John Quincy Adams, the sixth US president.
On the ground floor, don't miss the beautiful 17th-century font cover by master woodcarver Grinling Gibbons. Free 20-minute tours run from 2pm to 4pm most weekdays from April to October.