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

The second-deepest known cave on Earth, hidden in an extremely remote mountain region.

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

Small church on top of a huge rock column.

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

The first skyscraper to include a Ferris wheel built into the facade.

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

The charmingly disheveled clock tower of Tbilisi's puppet theater.

Ancient rock-hewn town that witnessed key events of Georgian history.

Underground monastery and fortress.

This half-forgotten fortress was constructed by the Ottoman conqueror of Constantinople.

A tiny park in the middle of some big power politics.

A section of the long chain that blocked enemy ships from entering Constantinople.

This beautiful train graveyard is one of the largest collections of steam locomotives in the Mediterranean and Europe.

This column celebrates Rome's victory over the Goths, and may be the oldest Roman monument in Istanbul.

Unfinished monument to peace between Turkey and Armenia, long divided by a dispute over genocide.

The legendary luxury train passage is commemorated with a charming museum inside its former eastern terminus.

Climb a steep hill in 90 seconds on the second-oldest urban subway in the world.

This ancient subterranean megalopolis is known for the hot oil traps that were installed above each of its entrances.

The best-preserved ancient theater in the world.

A fountain standing as a testament to a doomed alliance.

A charming beach town in Turkey captures all the colors of the rainbow.

Flames have been burning within this mountain for more than 2,500 years.

Ottoman-era houses lovingly preserved.