This eye-popping Icelandic crater lake is surrounded by red volcanic rock.

One of the tallest buildings in Iceland, and perhaps, the most visually impressive.

Medicinal spa created with the discharge from a geothermal energy plant.

Daily jousts and dancing barrel makers in Munich's mechanical clock.

God's Saharan sandbox of wrath.

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

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

An awe-inspiring mosque in Morocco with one of the tallest minarets in the world.

Morocco’s modern capital was once a haven for Barbary pirates, who went so far as to establish a republic of their own.

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

The other side is actually green.

This picturesque horseshoe weir was first built in the 1600s to prevent flooding in the town of Bath.

Local legend says Isaac Newton built this footbridge without any screws, bolts, or nails.

A remarkable medieval structure born from a 14th-century disaster.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

One of two giant blue cockerel statues erected with an intentional double meaning.

Equal parts record-breaking temple to consumerism and bizarre fun park, it's more than you think it is...

A toweringly silly piece of modern art has been delighting locals since the 1980s.

Once described as the "Eagle's Nest," this ruined ancient city rests on a remote mountaintop.

Five sultans and their families rest in eternal splendor, teeming with overlooked beauty and drama.

A winding path built in secret on the edge of the continent.

This half-forgotten fortress was constructed by the Ottoman conqueror of Constantinople.

Climb a steep hill in 90 seconds on the second-oldest urban subway in the world.

The ancient latrines of the Greeks, in all their public glory.