The oldest (maybe) swimming pool in Iceland is a stunning oasis built into the side of a lush hill.

One of the tallest buildings in Iceland, and perhaps, the most visually impressive.

The unique waterfall in Iceland's south features a backdrop of geometric black lava columns.

This elegant arc of a waterfall marks a religious turning point.

A church of bones, decorated with 40,000 human skeletons.

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

The history of occult science is turned into a creepshow at this lurid Prague tourist attraction.

Two stunning 17th-century libraries and a cabinet of curiosities.

Despite attempts by local police to discourage it, Beatles-inspired graffiti has been a means for artists to air grievances for decades.

Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.

Macabre astrological automaton clock dating to the late 1400s.

A mocking tribute to the past and modern leadership of Prague.

Monument to a suicide protesting the Soviet invasion.

Looming communist pillar with a Czech twist.

Museum dedicated to the terror regimes of Hungary.

340-foot statue built to honour the Heroes of the Soviet Union.

The eerie burnt-out remains of a prominent building where 30 protestors lost their lives.

The deepest metro station in the world.

One of the largest museums in Ukraine remembers the story of the German-Soviet War in iconic, brutalist style.

This attraction was abandoned after the Chernobyl disaster.

The ghost town left by the worst nuclear disaster of all time is being taken over by nature and urban explorers.

This derelict superstructure was a very important warning system for the Soviet military.

The European towns of Brașov and Râșnov each have proud signs reminiscent of the Hollywood sign.

An abandoned saucer-shaped monument in the Bulgarian mountains.