Remnants of cells from the most notorious London prison may lie in the basement of a rare Victorian Gin Palace.

A network of concealed passageways lies within a busy London Underground station.

The largest of London's subterranean rivers and once a mad, bad center of London life.

Scattered throughout London are ancient remnants of the city's former bounding wall.

An alleyway plaque is all that remains of the independent Texas' envoy that forgot to pay their rent for over a century.

The remains of Crystal Palace Great Exhibition of 1851.

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

An unusual round church in London with a Templar past.

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.

The perfectly preserved underground rooms where Churchill plotted the war against Germany.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

Hidden away in the city of Madison, Wisconsin is a nearly forgotten home that Frank Lloyd Wright built for a childhood friend.

The arboretum whose marshy soil sucked up the dreams of housing developers.

Built in 1931, this small passageway is believed to be the first modern skyway.

A Norwegian church that was built before Wisconsin was even a state has been entirely moved to a nicer spot.

The home where a lovestruck Fitzgerald wrote his first published novel, "This Side of Paradise."

Vice President Humphrey's final resting place is tucked away in this cemetery along with a few other notable figures.

This iconic water tower and failed bandstand is open for panoramic views once a year.

The oldest continually used church in Minneapolis also sells great meat pies.

Eight "Guardians of Health" protect this art deco water tower from pollutants and bacteria.

Enter the Forest of the Elves.

This lab's maddening silence is good for business but bad for sanity.