The roof of this ancient mausoleum is made from a single Istrian stone weighing a massive 230 tons.

A medieval, mosaic-lined baptistry built by a heretical Christian sect.

Psychoanalyst Carl Jung reported a paranormal experience after visiting this mosaic-lined Roman baptistry.

Filled with goldfish swimming in a shallow pool of sea water, this ancient crypt is more wishing well than burial site.

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

A small island in Lake Garda that was used as a burial site, pirate hideout, and a monastery.

Legend says the only thing buried within this magnificent tomb was a dog.

This Roman monument is surrounded by more recent construction, offering a stark contrast between ancient architecture and the modern urban landscape.

A star-shaped fortress town fort built in the geometric model of the Renaissance utopian city.

This unassuming chapel in Portugal plays host to a ghoulish collection of bones.

Picturesque intersection of witchcraft and ancient Christianity.

A chunk of the "true cross" is held in this small Portuguese church where modern day exorcisms are said to be common place.

This castle has links to Portugal’s founding and struggles for independence.

Perhaps the most spectacular grotto along the Algarve coastline.

A windswept necropolis carved into the rocks overlooks the "most Portuguese town in Portugal."

One of the largest Roman settlements in Portugal.

Ancient catacombs form the foundation for this Rococo orgy of a church.

"Portugal's Stonehenge" is made up of nut-like stones aligned with the heavens.

A stunning 18th-century site where pilgrims ascend by a series of punishing stairs only to return via funicular.

A 16th century chapel decorated with bones, skulls, and entire bodies hanging from the wall.

This small chapel is built of human bones and decorated with a golden skeleton.

This cathedral hides a sculpted dog that determines your fate and an unexploded shell from World War II.

The naturally mummified body of a peasant girl saint.

This bustling Italian plaza is built on the ruins of an ancient Roman amphitheater.