Elaborate tile work in this railway station tells the story of Portugal.

A jewel of the Mexico city skyline now slowly crumbles after surviving an earthquake.

A flooded Mexican cave that hides a river beneath the water.

An ancient system of freshwater caves filled with animal bones, including that of species long-extinct.

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 portion of a lovely Belize beach is infested with (harmless) sharks and rays.

A massive underwater sinkhole made famous by Jacques Cousteau.

The ruins of an 800-year-old monastery boasts the tallest round tower in Ireland.

This modest plaza in Moneygall, Ireland has cashed in on its distant connection to the U.S. president.

This 14th century tower house was once the home of Irish poet W.B. Yeats.

A hugely vast Irish landscape of barren rock that stretches for miles.

This singular Irish dolmen is more Frank Lloyd Wright than upright stonehenge.

This controversial Irish show cave is home to a massive formation known as the Great Stalactite.

Single runway interrupted by a busy road that cuts across its middle.

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

God's Saharan sandbox of wrath.

One of the most spectacular canyons in the world.

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

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

Traditional 11th-century outdoor tannery.

Crumbling necropolis set high above Fez.

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