The ruins of an abandoned medieval city where the last Byzantine emperor was crowned.

Burial grounds for more than 1,000 bodies deep under the modern town of Rabat.

This church on a Tohono O'Odham reservation has stood since 1797.

A statue of the beloved storybook character stands in front of the building in which her creator was born.

Spanish architects used seized Muslim gravestones to rebuild parts of the fortress.

A chapel on a volcanic core, marking the end of a successful journey.

Unable to build support structures on glaciers, the engineers for this tramway were forced to design a unique system.

A charming little museum founded by the designer of the Statue of Liberty.

Trek up this glacier before it disappears.

One of the largest ochre quarries in the world, hidden in a limestone landscape.

This French castle is said to have once held the Holy Grail but is now a gorgeous mountaintop ruin.

A natural arch carved by a river gave its name to the so-called "Cave of Forgotten Dreams."

These quaint French houses dangle precariously over a precipice.

Historic medieval fortified city in southwest France.

The mental institution where Van Gogh created some of his most famous work now allows guests to walk in the artist's footsteps.

An icy lake tucked among jaw-dropping alpine panoramas.

The lowest point in North America is home to an undrinkable pool surrounded by fields of geometric salt flats.

Giant eggs, walls of bread, and nightmare surreality mark the largest collection of works by Salvador Dalí.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

Bridge that died in war and was resurected.

A chain of 16 wondrous lakes formed as a result of the gradual dissolution of soluble layers of bedrock.

A mocking tribute to the past and modern leadership of Prague.