The enchanting archway is the only surviving portal into Dublin's lost medieval wall.

Underground monastery and fortress.

Take respite inside this jaw-dropping church while climbing the volcano where Georgia's Prometheus was once chained.

A cylinder monument with a spectacular vista commemorates a friendship that some say never existed.

These Stalin-era industrial 'death traps' hang lifeless above the city

Rock-hewn monastery complex with hundreds of cave structures tucked away into the mountainside.

The maze-like transportation hub contains abandoned areas, derelict stores, and a resident bat colony.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

Once the home of a hermetic monk, this cave now houses a small church.

This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

Legacy of the earthquake that nearly wiped Lisbon off the face of the Earth.

The world's oldest bookshop still in operation.

This abandoned five-star hotel is now a five-star urban exploration destination.

Bell tower juts out from a village buried under a lake.

A stunning hermit's shrine on a steep rocky spur in Northern Italy.

Europe’s oldest natural human mummy.

The rust covering this old mine's abandoned buildings matches the red pigment it once produced.

Local legends say that fairies used to dance in the moonlight here and invite handsome young men into their grottoes.

This abandoned coliseum was intended to be a grand Nazi rallying ground before it was halted at the end of the war.

A castle from the Holy Roman Empire that hosts traveling youth... in its stables.

These 18th century gardens tell a rocky story of the son of Odysseus.

Kenyan restaurant is a carnivore's paradise, serving exotic meats at its ultimate 'Beast of a Feast.'

Life and death are on parade at the most reliably perilous site of “the Great Migration.”

After sunset the heart of Zanzibar's historic Stone Town neighborhood transforms into a culinary playground.