The Guardian of Tallinn.

Island wonderland for communist autocrats.

A bit of the Berlin Wall was gifted to the Icelandic capital to commemorate the 25th anniversary of German reunification.

Iceland's largest geothermal mud pool is a little bit haunted and a little bit dangerous.

The picturesque birthplace of Icelandic democracy is drenched in the blood of its brutal past.

If a glacial river suddenly diving into a sheer chasm via a dramatic, multi-stage waterfall isn't peak Iceland, it's certainly close.

This valley of hot springs and boiling mud pots is home to the record-holding "Geysir," which originated the English word.

Walk in the footsteps of the gods and straddle two tectonic plates.

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

For a brief time in 1960s France, families could climb into a tiny submarine and be pulled along an underwater journey.

Site of one of World War I's most horrific scenes.

This ancient Roman bridge and aqueduct still stands as a wonder of classical construction.

This life-size replica of the Statue of Liberty's flame is also a tribute to Princess Diana by default.

This historic island prison holds one of the dungeons from the Count of Monte Cristo even though it is a work of fiction.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

The very center of Paris is surrounded by a bevy of strange good luck rituals.

The haunting complex honors the millions of Ukrainians who died in the forced famine under Soviet rule.

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.

One of the most poignant ruins of the Chernobyl nuclear disaster, the local football team's stadium has been quickly reclaimed by nature.

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

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.

An ornate plague column – built to celebrate life – claimed the lives of numerous artisans during its construction.