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.

This raised bulls-eye visible from space was the subject of an intense geologic controversy.

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

Once a menacing challenge for trailblazers, this trail is now the most scenic drive in Utah.

Bizarre lunar-like landscape with thousands of large stone "hoodoos."

This rugged area of red rocks and arches is often considered one of the most beautiful places on Earth.

Here, at the "world's longest art gallery," you'll find forty miles of ancient petroglyphs and pictographs.

In the world's most bombed country relative to its size, this incredible organization helps pick up the pieces.

When the USA donated cement and funds to expand the airport in Laos, the Laotians built a massive monument instead.

More than 200 statues filled with cryptic symbols give this park spot an aura of horror vacui fantasy.

A small 12th-century temple surrounded by waters believed to have curative properties.

This collection of reclaimed landmines acts as both an exhibition of their deadly history and as a shelter for children affected by them.

Take a hidden path to the mouth of the cave to watch millions of bats swarm at sunset.

Khmer Rouge's high security prison.

One of the biggest markets in Asia, under one of the continent's largest domes.

This impressive clifftop temple was once at the center of an international custody dispute.

A battle between nature and architecture in the Cambodian jungle.

An enormous Buddha peers through a gap in its ruined chamber.

This dazzling Buddhist temple was constructed from over one million ceramic tiles salvaged from a British shipwreck.