Ruins of a 13th-century fortress perched above a breathtaking Mediterranean bay.

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

The remains of a military communications outpost still stand on this Greek island.

The ruins of this monumental city founded by the first Roman Emperor are strangely overlooked by most travelers.

Monasteries on rock pillars, once accessible only by frayed ropes.

Local lore says two enemy dragons live within these breathtaking mountain lakes.

A scenic UNESCO site that doubles as a habitat for various forms of wildlife.

The oldest arboretum on the Dalmatian coast doubles as the gardens of Kings Landing in "Game of Thrones."

This narrow fjord-like bay is the largest ria in the Mediterranean Sea.

The Renaissance-era courthouse is a relic from the fortified town's centuries of Venetian rule.

Croatia's "hairy stone" fortress is one of the most well preserved Istrian castles.

Deep underground, the rusting remains of a German water pumping station from World War II.

A miniature train-ride through Slovenia's largest cave system.

With its mine closed, this old village is starting to resemble a ghost town.

A site where “the ravages of the war are more striking…than any other place in contemporary Spain.”

This tunnel was built in order to protect the village of Daroca from flash floods during rainy seasons.

"Alleys of Stone" form natural mazes in Spanish natural park.

Locals use these rock pools and waterfalls for swimming and cliff diving.

The runoff from these fiery cliffs sends red water flowing into the sea.

Fabulous formations, weird and wonderful wildlife.

The centuries-old trees lining both sides of this dirt road may become Madagascar's first natural monument.

This underwater cave in Madagascar is home to what is thought to be the country's largest fossil graveyard.

The abandoned tower is the last remnant of Lusaka's first major power plant.

The petrified remains of 150-million-year-old trees can be seen in and among the houses of the local villagers.