A Harvard-area eatery preserves the uncovered tiles of its century-old predecessor.

Memorial to a beloved puppeteer as well as all street performers.

This tiny, painted door at the base of a tree stump has been a fixture of the Harvard University campus for decades.

Impossibly life-like natural history models created out of glass by a father and son.

Three prestigious academic collections come together to create a world-class natural history museum.

The statue of John Harvard isn't actually John Harvard—or even, technically, the founder of the school.

This cemetery served as the only official burial grounds in Cambridge for nearly 200 years.

The etchings on this narrow channel between two islands bear witness to maritime travelers who have passed through since the Middle Ages.

The former Nazi Germany concentration camp stands as a museum to remember this dark chapter in European history.

An underground city of salt.

This Polish cave has housed a dragon, a brothel, and an enduring legend.

This grubby wall is said to be one of the Earth's esoteric energy centers.

St. Mary's features one of the most spectacularly decorated cathedral interiors in all of Europe.

Get past the gatekeeper's apartment and enter an elaborate hoax of a restaurant with a Masonic feel.

One of the most spectacular bridges in Spain spans a narrow chasm that divides the city of Ronda.

A small island dotted with old, historic Finnish buildings.

Pyongyang’s Arch of Triumph is the second tallest triumphal arch in the world.

One of the largest public squares in the world, named after the former DPRK supreme leader.

This North Korean pegasus statue was built as a symbol of the speed and perseverance of North Korean workers.

A symbol of the Workers' Party of North Korea.

Captured in 1968, the Cold War spy ship is the only U.S. Navy vessel being held by a foreign government.

A vast museum devoted to North Korea's victories against its imperialist enemies.

A highly symbolic tower in honor of Supreme Leader Kim Il-sung's personal philosophy.

North Korea's massive "hotel of doom."