A number of craters left by fatal mortar strikes have been filled with red resin to remember those lost during the Siege of Sarajevo.

The first mosque in the world to receive electricity.

Oriental bazaar in the heart of Sarajevo.

A museum dedicated to the former country.

One of Serbia's oldest luxury hotels and a nostalgic echo to Yugoslavia in the state's former capital.

A pair of connected skyscrapers form this symbolic gateway.

Destroyed Serbian army headquarters sits half crumbled in a largely revitalized Belgrade.

This striking, historic hotel has major Wes Anderson movie energy.

This small bronze pyramid marks the center of Belgrade, but some say it is a Masonic symbol.

Arguably Belgrade's only example of pure Art Deco architecture.

A towering spire in the fortress of Kalemegdan honors the victorious armies of Serbia during their struggles against the Ottoman Empire.

A misnamed well, with a deep dark past.

This Hungarian castle was built out of cardboard and wood until it proved so popular that it got upgraded to stone.

According to myth, Zeus himself was hidden in this cave to escape being eaten by his dad.

This little Greek plateau is home to thousands of rustic, white-sailed windmills.

A minotaur, a labyrinth, and a dubious restoration pull in visitors from around the world.

Estonia's largest creative city is a vibrant bohemian hub located within a former industrial complex.

During the Soviet era, the spire of this longstanding church was used as a radio transmission tower.

Walk along the medieval fortifications that have been protecting Tallinn since the 14th century.

The Guardian of Tallinn.

An empty relic of the Moscow Olympics crumbles away in Estonia's capital.

This former KGB building is now a museum memorializing the people who suffered during the Soviet regime.

Travelers who fall victim to this mermaid's charms are destined to stay in Užupis forever.

This micro-nation may be some sort of prank, but its constitution sure seems official.