A 1,215-foot tunnel transports pedestrians beneath the River Thames.

An easily overlooked stretch of ornate window fronts and gaslight lamps that could be right from the pages of Dickens.

The remains of Crystal Palace Great Exhibition of 1851.

Eighty million natural history specimens call this gargantuan museum home.

A vast overgrown cemetery, once known as one of London's "Magnificent Seven."

The only university zoological museum in London houses extinct animals, bizarre natural history specimens, and a Micrarium of microscopic creatures.

A subterranean ice warehouse that has lain hidden beneath central London for over a century is now open to the public.

Winding paths and ramshackle mausoleums in the oldest "park cemetery" in London.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the Harry Potter films.

Contrary to what one might expect, ice forms inside this small cavern during the summer and melts during the winter.