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

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

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

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

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

A beautiful chapel on the hills of the Oltrepò Pavese claims to house the tomb of King Edward II of England.

Iceland's "Smoky Valley" is a beautiful river that is shrouded in a constant cover of steam clouds.

This eye-popping Icelandic crater lake is surrounded by red volcanic rock.

This little train station is forever immortalized in film history.

According to legend, this cavern holds the passage that Persephone used to travel to and from the underworld.

Some of the greatest minds in the history of Hungarian art and science converged in this café.

Occupied for six centuries by Franciscan Order nuns, this monastery is an amazing ode to Catalán Gothic architecture.

One of the last remnants of the city's Chinese nightclub scene is now a dive bar selling killer mai tais.

Constructed during the 7th century this is one of the oldest largely intact Christian churches in England.

A functioning Roman-era aqueduct and bridge in rural southwest France.

This fortress played a key role in the battle that would ultimately give rise to the Maratha Empire.

Tucked in Mumbai’s wealthiest neighborhood is one of the city’s oldest and most sacred sites: a temple complex believed to house the waters of the Ganges.

The place of worship for Zoroastrians, Mumbai's Parsi fire temples use fire and ash for purification.

A nearly unconquerable island-fort in the Indian Ocean.

This ancient fortress was once the setting for a strange battle won with the help of a lizard.

Ancient snack bar of the Roman Empire re-opened.