Light still pours into the ruins of this ancient Islamic observatory.

You'll find just about anything in this funky Tbilisi flea market.

This architecturally eclectic fortress witnessed centuries of bloody turmoil, including the massacre of its ruling clan.

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

An abused and forgotten metropolis, abandoned for centuries.

Fast food feels like fine dining at this award-winning modern Georgian building.

The sixth of London's "Magnificent Seven" cemeteries, and a source of unlikely inspiration to Beatrix Potter.

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

A monument to the thrice mayor of London who according to lore made his fortune by selling his rat-chasing cat.

Ruins of a German castle on top of a towering stone pillar.

A pair of connected skyscrapers form this symbolic gateway.

Vienna's diversity-themed traffic lights were inspired by the Eurovision Song Contest.

The Habsburgs' royal collections of art and wonders.

Legends surround an ancient tree trunk riddled with nails for good luck.

The largest public library in the United Kingdom was designed to reflect the industrial and artistic history of the city where it stands.

The highest peak in Wales is said to be the final resting place of a giant killed by King Arthur.

This trio of neolithic stone monuments are fabled to be a king and his knights that were petrified by a witch.

The famous polar explorer stands outside the Royal Geographical Society's headquarters.

Step back in time and witness the fall of Constantinople.

Turkish adventurer antiques in the heart of the Grand Bazaar.

Tourists often confuse this beautifully ornate former cigarette factory for a mosque.

When the rain falls, this drain system turns into a musical instrument.

This Slovak bridge is known both for its connection to a national uprising and its UFO-shaped eatery.

Brass plaques embedded in pavement preserve the memories of those who lost their lives at the hands of Nazis during World War II.