The little church's beautifully frescoed ceiling has earned it the nickname “the Sistine Chapel of Madrid.”

Abandoned for decades, trains still pass through the now-restored remains of one of Madrid's first metro stations.

These three pillboxes still remain as a witness of the Spanish Civil War in a park of Madrid.

The morbid items in this small and hidden museum are not for the weak stomached.

This 16th-century monastery has been turned into a surrealist architecture compound.

Ever loyal to Roma, the small village of Albe in the Abruzzo region carried on until an earthquake did it in.

A magnificent Neogothic tomb hides within this Italian fairytale-like forest.

This picturesque Umbrian city has a subterranean side that has long remained hidden.

The “Sistine Chapel” of the Middle Ages merges 11th-century science and religion in wondrous hues.

Naturally preserved bodies are eerily staged throughout the crypt in varying poses.

A dreamlike medieval church dug into the tuff rock, with unusual carvings and possible traces of the Templar knights.

Knights Templar are visible inside this stunning Cistercian abbey.

Ruins of a 10th century church tucked away deep in a botanical garden.

This quaint Italian town keeps losing ground as the sides of its plateau slowly erode.

Romans built the world's tallest artificial waterfall in 271 BC.

The second-highest village in Lazio has attracted artists for 400 years and is now a spectacular open-air art gallery.

This unusually shaped fortress houses a blend of centuries-old frescoes and modern art.

This Romanesque church is built over the tomb of a martyr who legend says defeated a dragon.

A 16th-century horror show built in a lovely Italian garden.

Ancient, mysterious stone altars are hidden among wild woods in central Italy.

This ancient altar emerges from the thick forests to reveal the mysteries of Etruscan sacrificial rituals.

Wandering this ancient burial place offers a glimpse of the afterlife in the fresco-adorned tombs of an ancient Etruscan civilization.

A fascinating assortment of cave dwellings, medieval ruins, and sarcophagi are being devoured by the forest.

The ruins of an abbey believed to have been founded by Charlemagne in the 9th century.