The underground sanctuary of a mysterious ancient cult.

Architectureal fantasy quarter of Rome.

Natural cathedral designed by Italian artist Giuliano Mauri.

Rebuilt remains of a temple to Roman god Mithras.

This ancient market is often referred to as the oldest shopping mall in the world.

A medieval fountain lined with 99 unique stone faces whose origins and meaning remain unknown.

Conspiracy theories and occult legends surround this mysterious natural rock formation.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

Built to test magnetically levitated elevators, the tower also boasts Germany's highest visitor platform.

A spiral staircase twists to the top of this unusual Czech lookout tower.

The site of the first battle of World War II.

Spring that emits water and fire at the same time is said to have remedial properties, and sparked its own religion.

A Turkish monastery tucked into a cliff wall.

Local legend says that whoever burns down this 2,000-year-old tree will only have seven days to live.

Nestled in a peaceful valley, this Armenian monastery may have been saved from Mongols thanks to the eyes of God.

Atop a small Armenian hilltop adorned with many forms, and carvings, these stones tell a whimsical tale from a fictional world.

Armenia's premier center of astrophysical research was established during the Soviet era.

An abused and forgotten metropolis, abandoned for centuries.

The macabre collection of Jacques Sirgent, an expert scholar on the undead and all of their trappings.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

A collection of abandoned typographic signs from Berlin and beyond.

A state-of-the-art medical facility from the Imperial era is now a derelict ruin.

Thousands of rusting train cars have been slowly falling apart on the edge of Greece's second largest city.

World's largest crossword puzzle spans the side of a towerblock, its clues scattered throughout the city.