These crumbling Latvian forts make for some haunting seaside ruins.

Flamboyant architecture from the turn of 20th century.

3,000 market stands in five former Zeppelin hangars.

From Austrians to Nazis to Soviets, this historic Budapest fortress has a history as complex as the city itself.

A fake Transylvanian castle houses a cathedral of antlers.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

Baroque celebration of the end of the Great Plague of Vienna.

Op-art architecture designed for happiness.

The Habsburgs' royal collections of art and wonders.

The beautiful baroque library of the Hapsburg empire.

The final resting place for the remains of 143 Habsburg royalty.

This artificial cave looks like something out of a fairytale.

Synagogue built from the stones of Solomon's temple contains the golem of Prague.

Most-visited and most-photographed slot canyon in the American Southwest.

Gargantuan home of Russian science.

Stalinist skyscraper built with help of cryotechnology.

The tallest hotel in Europe.

World's largest bell sits on the grounds of the Kremlin in Moscow.

Moscow's most popular cemetery includes the graves of numerous cosmonauts.

Former headquarters of the KGB.

Museum celebrating the achievements of the Soviet space program.

Metro station with a claim to rock n' roll fame.

Cold war icon and onetime "hole" in the iron curtain.

In this truly magical place, rent hasn't been raised since the year 1520.