This glass skywalk offers vertiginous views down the volcanic cliffs to the beach below.

Men in rubber-soled boots serve as your "brakes" on this toboggan ride Hemingway described as "exhilarating."

This triumphal arch celebrating the Sun King's conquest of Lille is a masterpiece of military architecture.

A serene memorial that honors the adventurous spirits of climbers who lost their lives in the High Tatras.

Communism's topsy-turvy effect on Poland has been brought to life in this wacky tourist trap.

This imposing 20th-century castle was abandoned before it was ever completed.

The titular "little arch" near this Italian resort is one of the most popular diving spots in the country.

At an estimated 3,800 years old, this olive tree is one of the oldest on earth.

A striped 12th-century basilica sits in the countryside of Sardinia.

Stalactites and stalagmites in a beautifully lit cave.

Greenery covers the face of a gently-dripping waterfall deep in the mountains of central Sardinia.

Ancient cave tombs known as the "houses of fairies."

A collection of sculptures that explore what's at stake when nature is thrown out of balance.

"There's nothing there," and other lies the KGB told us.

Disused seaplane hangar gets a second life as the jaw-dropping home of Estonia's museum of maritime history.

Rubbing the buttons along this statue's coat is considered good luck.

The widest natural waterfall in Estonia is a sight to see in all seasons.

The first monument in Estonia that was made by an Estonian sculptor.

This striking memorial is one of Estonia’s most controversial Soviet leftovers.

This dizzying tower was built to better broadcast the 1980 Moscow Olympics.

During the Soviet era, the spire of this longstanding church was used as a radio transmission tower.

A monument commemorating the 852 lives lost in the sinking of the MS Estonia.

Estonia's largest creative city is a vibrant bohemian hub located within a former industrial complex.

An empty relic of the Moscow Olympics crumbles away in Estonia's capital.