This Nazi ruin was the site where Hitler was almost blown up by a suitcase bomb.

The homestead of American patriot John Adams.

The romantic botanic tunnel feels like a well-kept secret.

The remains of a town so thoroughly destroyed by French forces that the citizens simply left.

A centuries old castle atop a dormant volcano houses museums devoted to both women and witches.

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

Panoramic views of the city of New Haven and the Long Island Sound, with a side of history.

Local lore holds that Butch Cassidy took an escape route through Red Canyon's sandstone hoodoos after an attempted murder.

Commemorating the spot where the famous scientist fed his pigeons.

A spiral staircase twists to the top of this unusual Czech lookout tower.

While only two of the ancient buildings at this site are actually churches this was one of the earliest Irish pilgrimage sites ever.

The site of the first battle of World War II.

The vast chamber inside this abandoned cooling tower looks like something out of a sci-fi dystopia.

High atop a Mexican rainforest mountain, this ancient pyramid once drew pilgrims countries away.

This isolated island is often capped by its own fluffy cloud.

The largest man-made crater in the U.S. marks the spot where we once tested mining with nukes.

Little island known for its massive beachfront "flowerpot" pillars.

The world's largest wooden trestle stretches across this desert canyon in Anza-Borrego Desert State Park.

This abandoned NASA launch site is now a memorial to a trio of astronauts who were killed there.

The world's first commercial spaceport is a disappointment of cosmic proportions.

Secret US military film studio in the Hollywood Hills.

This extraordinary geological oddity resembles human-made pavement.

For those with no fear of heights: a skywalk 4,700 feet up on a Chinese mountain.

This building holds the embalmed remains of the leader of the Bolshevik Revolution.