A lone tower rises above the cliffs in a city park, offering fantastic views of the Connecticut landscape.

This former insane asylum now holds a pathological anatomy museum.

Built to give thanks for the passing of a plague epidemic, this cathedral is a one-of-a-kind architectural hybrid.

What looks like a suicide in progress is actually a statue of Sigmund Freud.

The mummified right fist of a 1,000-year-old saint-king sits inside an ornate golden reliquary.

Handsomely crafted representations of our round planet.

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

Museum devoted to the artificial language of Esperanto.

This one-time health resort was used by aristocrats around the world.

This massive subterranean fissure is known as the "underground Grand Canyon."

Castle and secret tunnel withstood a siege until its owner was killed by the Holy Roman Empire, while sitting on the toilet.

An eclectic art form practiced by untrained masters is celebrated at this museum in the heart of Zagreb's old Upper Town.

This scale model of our solar system hid in plain sight for years before a physics team sought out all the planets.

Where the lovelorn find a home for their sentimental keepsakes.

This pump on the bad side of Victorian London betrayed a horrifying revelation about the water supply.

This South London cemetery holds the remains of more than 15,000 people.

A mysterious pair of mice eating a piece of cheese is London's smallest public sculpture.

A sculpture outside London's oldest cathedral honors the Mohegan chief who died while petitioning the king.

The last remaining example of the boatmen's perches that once dotted the south bank of the Thames.

Murals of the wild parties once held on the frozen River Thames.

This one has sailed five times as far as Sir Francis Drake's famous ship.

The commemorative stone column conceals a secret laboratory.

One of the few remaining casualties of the London Blitz, this destroyed church has become an enchanting public garden.

This legendary stone is of unknown origin, and throughout history has been a literal touchstone for British leaders.