The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.

A collection of 100 brains preserved in jars on the UT campus.

The mystic whose incorrupt corpse still attracts the faithful.

This colorful creation wasn't always a welcome part of Toronto's Moccasin Trail Park.

This almost-forgotten underground dungeon housed several convicts over the years, including Caravaggio.

The iconic boulevard is the perfect place to catch sight of a bicycling skeleton, a levitating Satan, or a chef with his head stuck in a pizza.

Single runway interrupted by a busy road that cuts across its middle.

The world's longest and deepest train tunnel.

One of the world's largest collections of pharmaceutical artifacts.

Hundreds of lucky felines haunt the ruins where Caesar was murdered.

Look closely and you’ll notice that the color changes a third of the way up the tower.

This massive, ancient stone was disassembled and then put back together again.

One of Canada's most incredible rare book collections holds hundreds of thousands of gorgeous tomes that the general public can touch.

The nude sculpture on this fountain shocked conservative townsfolk when it was first unveiled, but not as much as the dead body found in it decades later.

Visitors can walk over the largest concentration of Columbian mammoths to have died from one event.

A sculpture serving as an homage to Pope John Paul II.

This hill made entirely of ancient Roman jars was simply a garbage dump to the people of the time.

If you want to talk to the Pope you will have to stare down this surreal vision of Jesus rising from a nuclear hell.

This ancient Roman prison is decorated with an upside-down cross not as blasphemy but as saintly tribute.

A mysterious chasm in the heart of the ancient Roman Forum, the Lacus Curtius was once believed to be a gateway to hell.

Museum dedicated to literary greats of the Romantic Period is also the home in which Keats met his untimely end.

The "Greatest Sewer" of ancient Rome is one of the oldest sewer systems in the world, and is still in use.

One of the longest wooden benches in the world snakes around Geneva's Treille Promenade.

This long line of cement defensive wedges is named after the famous chocolate bar for obvious reasons.