This mountaintop beacon is only lit three times a year but shines like some kind of all-seeing eye.

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

The largest hot spring in the United States is, as the name suggests, a stunning show of natural color.

The stones of this Incan wall complex fit together so well you couldn't fit a piece of paper between some of them.

The second generation of a mighty volcano rises from the sea.

This natural Icelandic fissure allows divers to swim right between two volatile tectonic plates.

The Denver airport is guarded by a 32-foot-tall sculpture of a demonic horse.

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

A peculiar mansion built by the troubled heir to the Winchester Rifle Company fortune.

God's Saharan sandbox of wrath.

View the California coastline (and the home of Barbara Streisand) inch by inch with stunning, government-sanctioned aerial photography.

This prehistoric sinkhole lured exclusively male mammoths to their death, much to the delight of science.