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

Richard III supposedly disposed of his nephews' bodies here in an effort to seal his claim to the throne.

Created by one of England's most prolific labyrinth designers, inspired by Bath city history.

An ancient underground cultic temple where sunlight penetrates on the summer solstice.

The only quarter of the Old City not dedicated to a major world religion.

A "miracle" that seems to produce more holy fistfights than holy revelations.

An ancient tunnel in Jerusalem built to redirect water in the event of a siege is one of history’s great architectural innovations.

Descend 2,030 years into the past in an ancient tunnel built to support Jerusalem's most famous wall.

This luxury shopping lane has been protected by its own tiny police force for over a century.

Copenhagen's celebrated theme park and gardens.

The old observatory in Copenhagen has a spiral corridor used as a racetrack.

The de facto symbol of Copenhagen is this bronze fairytale which cannot seem to keep its head for very long.

The second-largest (of only two in the world) large particle collider is the underdog of experimental physics.

The site of a tragic massacre that spawned a multimedia franchise.

Along a busy beachfront strip you may hear Frank Sinatra singing from one boardwalk home.

Infamous marsh filled with toxic waste, World War II-era London rubble, and dead mobsters galore.

On the Hudson resides one of the largest clocks in the world.

A playground inspired by differential calculus dangles from the ceiling of the Liberty Science Center.

Historic town settled in the 19th century because of its convenient location along a popular coal transport route.

Step inside Lucy, the world's largest "elephant."

Series of storm drains connected to a dark urban legend.

A proud bronze billy stands as an eternal symbol of Ireland's oldest festival, where a goat is made king.

Perfectly preserved ancient monastery in an impossibly dramatic location on a rocky island in the Atlantic.

Famously misunderstood wonder of the ancient world