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

This one-time health resort was used by aristocrats around the world.

Castle and secret tunnel withstood a siege until its owner was killed by the Holy Roman Empire, while sitting on the toilet.

This unassuming museum's slogan translates to “there is a limit of sadness, anxiety has no limits."

A reconstructed medieval gateway that was the magnificent entrance to the capital city dating back to 1037.

The deepest metro station in the world.

A neo-Gothic mansion now houses a wunderkammer of analog tech that hits on all the senses.

An abandoned whaling station on an active volcano offers hot springs in Antarctica, surrounded by ruined giants of industry.

This Austrian museum celebrates the work of famous forgers and their inimitable imitations.

On a winding Vienna side street, one museum has turned their windows into a monument to history’s peace-minded heroes.

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

This cubist Vienna church building looks like some sort of alien stonehenge.