D.C.'s first central library was born out of a chance encounter with the philanthropist whose name it bears.

The national park was once a plantation estate.

The actual model from the original "Star Trek" series is now on display at the National Air and Space Museum.

There’s a hidden military meme engraved on the World War II Memorial.

Fittingly, America's museum of architecture is itself a magnificently designed old building.

This charming colonial alleyway is one of the oldest continuously used residential streets in the U.S.

Clap your hands at the base of the pyramid, and the song of a sacred Mayan bird will echo through the air.

An elaborate Mayan city shrouded in alien conspiracy revealed the tomb of Pacal the Great.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

Every equinox this Maya pyramid puts on a spooky ancient light show.

This neon blue river gets its color from a unique mix of bacteria and volcano minerals.

The designated Jewish quarter in Fez dates back to the 15th century.

The courtyard of this small Marinid madrasa is a dazzling example of intricate Islamic architecture.

This amazing oasis of art and plants is hidden on the outskirts of Marrakesh.

This former royal palace with gorgeous gardens became the first museum in Morocco.

The oldest known university in the world is in Fez, Morocco.

Traditional 11th-century outdoor tannery.

Along the most northwestern point in Africa is an ancient cave surrounded by legends.

World's largest film studio, where visitors tour the decaying sets that litter the harsh desert environment.

The other side is actually green.

One of the most spectacular canyons in the world.

Founded as a refugee camp, now a popular tourist spot.

An early 20th-century bullring converted into a modern shopping center.

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