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

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

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.

Classical ruins that remember ancient Rome's presence in Africa.

This dizzying span over the ancient Algerian city was once the highest suspension bridge in the world.

An extraordinary mix of Phoenician, Roman, early Christian, and Byzantine ruins beautifully set overlooking the Mediterranean.

The original resting place of Queen Cleopatra and Mark Antony's only daughter.

A 250-year-old timepiece-automaton adorned with golden mechanical birds, which still sing to this day.

An old hill fort covered in over 100,000 crosses is a symbol of Lithuanian nationalism and beliefs.

While this monument tile is shrouded in mystery it also marks the end of the longest ever human chain.

Legend has it that Napoleon Bonaparte fell in love with this Gothic church.

Travelers who fall victim to this mermaid's charms are destined to stay in Užupis forever.

This micro-nation may be some sort of prank, but its constitution sure seems official.

Latvia's symbolic mountain-shaped national library is home to millions of cultural tomes.

The oldest housing complex in Riga is a mini timeline of architectural trends.

A black cat protests the City Guild in Riga's Old Town.

Flamboyant architecture from the turn of 20th century.

3,000 market stands in five former Zeppelin hangars.

The oldest church in the Estonian capital is home to over 100 fantastical cemetery coats-of-arms.

Only a fragment of this 15th-century Dance of Death survives today.

The Guardian of Tallinn.

The largest salt lake in the Sahara is mysteriously alluring.

The oldest standing Byzantine church in Athens is tucked within a monastery in the middle of an upscale shopping district.