Austria's ultra-modern art museum looks like Cthulhu's giant alien heart.

The bizarre rocks of Đavolja Varoš are the result of natural erosion.

A Red Cross memorial museum at the site of the Niš concentration camp that operated for four eventful years during World War II.

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

A pair of connected skyscrapers form this symbolic gateway.

A Serbian church lit by chandeliers made of weapons.

For over 40 years, this quaint little house has teetered on a rock in the middle of a river.

This spaceship-like Serbian monument reaches for the stars in celebration of the fallen fighters of fascism.

This memorial park stands on the site of one of the largest mass executions of the Second World War.

A sinuous path among steep cliffs creates a stunning sight in southwestern Serbia.

Nikola Tesla's ashes are held in a golden sphere, surrounded by his works.

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

Structure built from the skulls of vanquished foes.

A Lycian city of the dead carved into the hillside of Southern Turkey, complete with startlingly human touches.

In this historic region, homes and churches are carved into ancient volcanic rock formations.

The deepest underground city in Turkey was designed to protect 20,000 people behind massive stone doors.

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

Iconic rock formations that allow for exploration during high or low tide.

Niagara Falls holds a special place in Nikola Tesla's history, so they put a statue on it.

This Niagara Falls tourist trap is a world bright with neon and curiosities that will inspire love, hate, or a mixture of both.

One of the Seven Wonders of the Modern World holds the world's tallest metal staircase.

Cliffs that hold fossils, including the earliest known reptile, dating back more than 300 million years.

Pennsylvania's own Roswell-style UFO mystery.

Frank Lloyd Wright's most iconic home dangles over a Pennsylvania waterfall.