A geological oddity topped with a 2,000-year-old pagan temple.

This Armenian monastery was carved out of cliffs and named after the spear used to stab Jesus.

This mysterious but iconic tapered tower appears in many Azeri fairytales and legends.

The building's fluid, wavelike walls are a true feat of architectural ingenuity.

A shrine of fire worship built on top of a natural flame.

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

Resonant stone, that has been played since prehistoric times.

Home to nearly a third of the world's mud volcanoes, Azerbaijan is home to a messy, bubbling, and sometimes explosive landscape.

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.

Amsterdam's former hotspot for public executions and dissections.

One of Amsterdam's narrowest houses is located right across the canal from its widest.

Visit the home of Sweden's beloved fictional character, Pippi Longstocking.

Stockholm's deepest subway station is also a stunning ecological wonder.

The dome-shaped reservoir of this old water tower produces unique acoustic effects.

A peat bog in southern Sweden provides a cozy and photogenic home for junked Volvos, Saabs, and the occasional American muscle car.

While not Turkey's deepest underground city, this subterranean redoubt is the largest.

When you can't get to the Pacific, just go to Florida.

The inspiration for the Patagonia Clothing logo, Cerro Fitz Roy turns pink at sunrise.

This stunning mass of ice spans 121 square miles and is still growing.

This sculpture pays homage to sailors that perished attempting to round Cape Horn.

Major tourist destination known for its bubbling mud-pools and hot thermal springs.

Deadly scalding and one of the largest hot springs in the world.