In Faroese legend, this sinister horse-shaped beast lures unsuspecting passersby only to drown them in the lake.

This remote island village was in danger of depopulating completely until a tunnel was built to connect it to the rest of the world .

This mysterious, medieval cathedral remains unbuilt but fiercely protected.

The unique waterfall in Iceland's south features a backdrop of geometric black lava columns.

Twisted girders are all that remain of an Icelandic bridge that was wiped out by a combination of volcanic heat and glacial floods.

This fairytale-like structure is the last turf church ever constructed in Iceland.

Iceland's largest lagoon is home to stunning multi-colored icebergs.

A black sand beach where glacial fragments wash ashore and look like sparkling diamonds.

This natural rock formation features seemingly unnatural vertical ridges that have been blamed on elves.

A 2,000-year-old computer demonstrates remarkable engineering and astronomical precision.

Gladiators once walked this ancient, subterranean passage.

This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

This historic structure has been used as a mosque, a barracks, a prison, a school, and a bakery.

An ancient octagonal weather station named for the eight Greek gods of wind.

This mystical orb covered in strange symbols is thought to have been used in ancient Greek magical rituals.

An ancient Greek monument and a Byzantine church coexist inside this cave.

The Cycladic architecture makes this Athens neighborhood feel like an island paradise hidden in the shadow of the Acropolis.

Heralded as the world's first theater, these ruins are often overlooked as they reside in the shadows of the Acropolis.

Legend says this sacred tree was a gift from goddess Athena.

A Byzantine-era church hidden in a wooded area below the Acropolis.

The enigmatic sculpture hides above an escalator in a Milan metro station.

An exclusive waiting room built for the royal family in the 1920s is hidden in Milan’s central station.

Artistic tombs, monuments, and a beautiful "Hall of Fame" lurk inside this cemetery.

Long-abandoned art nouveau baths beneath Milan's Piazza Oberdan.