A cluster of historic bathhouses built on the famed hot springs that gave the Georgian capital its name.

At this rare mosque in Tbilisi, Sunni and Shia Muslims pray side by side.

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

Hidden up a dusty track off the Georgian Military Road is this fascinating waterfall with mountainous views.

Fortified homes of highland warriors that are still in use today.

Ruins of a former government building destroyed during the Georgian-Abkhaz war in the wake of the fall of the Soviet Union.

A beautiful but deteriorating monument of Soviet architecture.

At first glance, this area seems like just another city park, but the lush landscape hides a dark past.

There are thousands of tributes and memorials to the King, but none quite like this one in a Kraków city park.

An ethereal glowing blue ocean cave in Croatia.

These gigantic skeletons tower over visitors and provide insight into the creatures that once ruled over Ireland.

The somber sculptures commemorating Irish Famine on the river Liffey in Dublin.

An 80-year-old plane tree is devouring an iron bench at Ireland's oldest law school.

One of Ireland's most infamous prisons for rebels including men, women and children.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

The decaying remains of a once-luxurious Soviet spa town.

Remnants of the most densely packed city in world history, that thrived on anarchy for 30 years.

Teeming with illegal goods and services, this towering maze of vice is also a popular tourist accommodation.

This hulking behemoth is actually five interconnected towers built in the 1960s.

This densely-packed cluster of buildings was saved from the wrecking ball and turned into an art community.

These charming mailboxes became social media stars after a typhoon failed to topple them.

Only through deep darkness and tragedy did this elaborate royal palace become a sacred temple.

The tangled roots of a giant banyan tree have fully reclaimed the ruins of this abandoned warehouse.

Grandpa Rainbow felt the neighborhood needed some color, so he picked up a paintbrush and went to work.