Millions of glowing microscopic organisms light up the waters of this luminous lagoon.

The legend associated with these ruins understates the splendor of the mansion that once stood here.

Italian horror legend Dario Argento’s own shop hides a sinister museum-dungeon in the basement.

One of just five sand-floor Jewish synagogues in the world.

This isolated Maya cemetery in Chiapas is distinguished by its towering, colorful wooden crosses.

One of the world’s most colorful cemeteries, where each pigment is symbolic.

The ruins of a world-renowned medieval hospital.

This grisly effigy displays an early Christian martyr who was skinned alive and beheaded.

Where royalty waits in the height of luxury.

Public water fountains built during the Ottoman Era still stand throughout this seaside town.

Venture into the past with an unlisted exhibit hall featuring extinct birds.

The eccentric mansion of one of the most popular horror authors of modern times.

The ruins of a 19th-century aqueduct run through this Brazilian island's deep forest.

This Brazilian town built by Freemasons is full of colonial Masonic architecture and symbolic imagery.

An architect transformed this abandoned cement factory into his castle-like workshop.

Seemingly grown on some other world, these New Mexico rock formations look like a disused science fiction set.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

The long-lost final resting place of an accused witch.

Not far from a popular beach, an unfinished, abandoned mansion for Bulgaria's last communist dictator.

A peculiar family mausoleum built by a German nobleman captivated by the occult.

This unique structure allowed boats to bypass underwater mine barriers in the channel to enter the harbor.

An expansive complex of subterranean tunnels is all that remains of one of Europe's most formidable medieval fortresses.

This tri-part waterfall is a little bit of fairytale beauty in the heart of Luxembourg's Little Switzerland.

Once the local rulers had gone these enchanting ruins housed common folk in an almost real life fairy tale.