A 1,000-year-old church holds the bones of the Christian martyrs who died hiding inside it.

This natural gas vent certainly earns its name as the smallest volcano in Italy.

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

A cave in southern Italy adorned with thousand-year-old Biblical frescoes existed in obscurity until fairly recently.

In a city that boasts four separate inclined cable railways, this is one of the busiest funicular lines in the world.

The burial place of an obscure North African saint was turned into a macabre body preservation factory for the 17th-century Neapolitan elite.

Artist Diego Morlin's war between the natural and human worlds is a wanderer's delight.

Nestled in the hills of Tuscany are gorgeous, multicolored hot springs.

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

One man's quest to fix his toilet unearthed over 5,000 artifacts spanning more than 2,000 years of history.

Stumbling upon this whimsical wooded garden is like stepping into an enchanted forest full of philosophical musings.

A gorgeous medieval library where the books are kept in chains.

An Italian geologic wonder that served as the inspiration for the landscape of Dante's hell.

Ride a boat through this magnificent underground world, which now doubles as a theater.

This curious building hides eclectic details like medieval gargoyles alongside naked angels and Art Nouveau mosaics.

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

The top of society once luxuriated in this world-class hotel, which continues to impress, even in ruin.

The Neapolitan Cult of the Dead still cares for the skulls at this mini-Fontanelle.

One of the most well-preserved castles in Italy also contains a rare medieval example of a port fortification.

A forgotten "city of water" underneath the famous Trevi district.

Crumbling ruins of the thermal baths that once attracted royals and aristocrats from throughout Europe.

A madman's personal garden filled with 1,000 sculpted heads.

Italian poet Dante Alighieri is entombed in this small mausoleum in Ravenna, and his hometown of Florence has never been too happy about it.

Deceased nuns were placed on stone chairs to decompose, while the surviving nuns prayed near the lifeless bodies.