A rehabilitation center for some of South America's most unique and endangered animals.

Only gap in the 30,000-mile span of roads called the Pan-American Highway.

A three-tiered waterfall plummets from a mountain cave with amazing views over the countryside.

This elegant Colombian fortress was one of the torture headquarters for the Spanish Inquisition.

This lake’s emerald green waters are a spectacular sight, but it’s not a great place for a swim.

One of the oldest colonial buildings still standing in South America.

This historic, palatial theater is now one of the world’s most beautiful bookstores.

A stunning blue-green lake located in the Terskey Alatau mountain range.

In the middle of a busy residential neighborhood, a small roofless church being reclaimed by nature.

A strenuous, unofficial trail leads to spectacular views in one of America's most remote national monuments.

This historical art colony is adorned with thousands of hand-carved concrete sculptures in the Mayan Revival style.

This Khmer-era temple includes a lintel that was stolen and displayed at the Art Institute of Chicago for years before returning to Thailand.

This Roman underground canal was the longest tunnel ever built until the late 19th-century.

Of five volcanoes located in the massive Tengger caldera, this cone is the youngest and most active.

The largest Roman amphitheater in the Balkans once held over 20,000 people, but managed to lay hidden for hundreds of years.

According to a local legend, this old castle could only be built after a woman was immured in the walls.

This river island in Sierra Leone is home to impressive biodiversity and the country's first community conservation program.

The secluded resting place of a local historical figure who perished during the sinking of the Titanic.

This pagoda was once the central feature of a Buddhist temple that no longer exists.

A room filled with frescos that make it seem like the walls are crumbling down while giants die in despair.

It took more than 300 years to build this church, which is home to two sacred vessels believed to hold the blood of Christ.

A small house sits between two huge rocks, with its back to the sea.

This crescent-shaped beach is said to glow under the light of a full moon.

This 200-meter-high waterfall marks the site of Achilles’s immortal baptism at the mouth of the River Styx.