The largest madrasa in Morocco once housed more than 900 students within its exquisite walls.

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

Fortune tellers, snake charmers, poets, and storytellers all gather on this historic square in Morocco.

God's Saharan sandbox of wrath.

Traditional 11th-century outdoor tannery.

Thousands of narrow alleyways in an ancient medieval city make up what's believed to be the world's largest car-free urban zone.

The other side is actually green.

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

A fortified city, home to a remaining population of five families

Mosaics, storks, and brothels—this ancient city has it all.

Limestone caves in the Cambodian countryside, once the site of genocide, now a place of peaceful beauty.

A hidden church in a hidden courtyard tells the story of the Miracle of Amsterdam.

In the days before house numbers, these colorful signs held clues about various buildings' purposes.

Famed for its pie, this eatery has a hidden tunnel that allowed Catholics to secretly walk to church during the Reformation.

This bird-loving brewery is situated in an old municipal bathhouse, nestled beside a 300-year-old windmill.

Amsterdam's former hotspot for public executions and dissections.

Three connected pink triangles memorialize persecuted gays and lesbians throughout history.

This city square is home to Amsterdam's oldest church and a statue honoring Dutch sex workers.

This 22-floor tower's Skydeck offers panoramic views of Amsterdam.

An Ancestral Puebloan ruin that appears to burst into flames in the sunlight.

One of the world’s largest collections of petroglyphs records 2,000 years of human activity.

A striking, menacing sandstone peak towering above a landscape that's equal parts Mordor and the Moon.

The fifth-longest natural arch in the world, and the longest outside China.

This gallery of prehistoric red ochre art lines the wall of a scenic segment in Utah's San Rafael Swell.