The largest stone moai on Rapa Nui.

Two very green residential towers cleaning the air in one of Europe's most polluted cities.

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.

An incredible mosaic-lined monument said to have held the remains of an ancient Roman empress.

This 6th-century church has the largest and best-preserved collection of Byzantine mosaics outside Constantinople.

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

Stuck in the arcade of Casa Isolani are three arrows of mysterious origins.

Legend has it this fountain built to symbolize the Pope’s power hides a strange secret concerning Neptune's manliness.

The ruins of the largest gladiatorial school in Rome are largely hidden under modern streets.

This ancient Roman prison is decorated with an upside-down cross not as blasphemy but as saintly tribute.

This large, circular tomb is the final resting place of the first emperor of Rome.

A Nesting Doll of Churches.

Hundreds of lucky felines haunt the ruins where Caesar was murdered.

This sculpture meant to honor the bravery of the Indigenous Mapuche people of Chile proved controversial.

Pablo Neruda's custom-built lover's nest was made to remind him of the sea and named after his mistress' hair.

A museum founded to reflect on and remember the human rights abuses under Chilean dictator Augusto Pinochet.

A beautiful deserted greenhouse in the middle of a park.