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

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

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

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

A spherical "micro-nation" in the heart of Vienna.

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

In one of the world's smallest countries, a royal's personal winery is open to the public.

One of the world's largest collections of pharmaceutical artifacts.

This massive underground salt mine now holds a sci-fi theme park in its depths.

Some call this eerie forest of crooked trees the "Bermuda Triangle of Romania."

The Natural History Museum that time forgot.

This Transylvanian church has changed its denomination four times.

The old observatory in Copenhagen has a spiral corridor used as a racetrack.

Climb to the top of its spiral spire for spectacular views of Copenhagen.

Danish tourist destination well known for open stalls where vendors sell marijuana on the street.

This ordinary street was made infamous by a legendary visit from the devil.

Site of the first radio and telephone broadcasting companies in Copenhagen.

The only surviving piece of Copenhagen's 16th-century defensive wall.

This once-grandiose behemoth of a monument from the socialist era now sits quiet and closed up.

This gem is often wrongly overshadowed by the larger, newer Metropolis church in Athens.

Legend says it was constructed with the destroyed pillar of an ancient Greek Temple.

The only surviving choragic monument is a trophy awarded in 334 BC for the winning dramatic chorus.

The oldest cemetery of modern-day Athens blends the modern and ancient worlds.

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