A massive collection of petroglyphs dating back some 40,000 years.

This Soviet-era athletic and recreation facility is the highest ice skating rink in the world.

This museum is dedicated to one of Russia's greatest explorers.

A modern tower, symbolizing the legend of a golden egg on top of the tree of life.

The first version of this stalwart construction appeared around 3,000 years ago.

This striking sculpture of Icarus honors Greece's fallen flyers.

The only surviving choragic monument is a trophy awarded in 334 BC for the winning dramatic chorus.

This symbol of Yugoslav liberation decorated with 620 carved heads of mythical creatures is now a forlorn relic of another time.

Abstract monuments express sorrow and resilience at the site of a horrific massacre in Nazi-occupied Serbia.

Concerts, art, offices, and a café in what used to be Berlin's first crematorium.

For patriotic Russians, this memorial honoring the Soviet soldiers who died liberating Berlin in 1945 is the most sacred location outside of Russia.

Berliners converted a bombed-out, disused lot into a community-run urban farm with its own cafe and bar.

The world's largest wooden structure.

According to the Guanches, the aboriginal people of the Canary Islands, the king of evil lives inside this volcano.

Single runway interrupted by a busy road that cuts across its middle.

Stone age urban planning.

This 14th century castle withstood years of battle but is now sliding off the hills into the Danube.

Through the colossal entrance to this cave you'll find limestone tubs and an underground waterfall.

A grand Yugoslav memorial to the group of partisans who fought and died resisting western Serbia’s Nazi occupation.

The interior of this Serbian royal family's mausoleum is covered with exquisite mosaics.

This spa park features an open-air museum of abstract marble sculptures.

A fairytale island floats in the middle of Italy's little-known Lake Orta.

This Italian pyramid is said to hold the mingled remains of the dead from both sides of the Battle of Novara.

Life's work of sculptor Elisabet Ney remains preserved in her last studio.