This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

A rare underwater observatory in the Caribbean that provides breathtaking views of vibrantly colored aquatic life.

Legend tells how a Spanish soldier disappeared from this isolated sentry box without a trace.

This colorful gate stands as an entrance to the walled city of Old San Juan.

Columbus' failed colony in the New World.

This statue celebrating everyday life in Dublin has a few unsavory nicknames.

The modern birthplace of Irish freedom.

Amidst the bustling streets of Dublin, there is a hushed garden that is dedicated to "All those who gave their lives in the cause of Irish Freedom."

The somber sculptures commemorating Irish Famine on the river Liffey in Dublin.

The house where the writer spent his formative years.

The comedy and tragedy of Oscar Wilde is preserved in a Dublin park, captured in a sculpture of colorful stone.

A museum that cashes in on its infamous little people while teaching you a thing or two about the Irish fey.

A long-buried ancient ruin unearthed right in the middle of the city.

A dead saint, a deadly poison, and a mysterious holy ooze.

Since 1999, this gelateria founded by a string instrument maker has been turning out some of Rome’s best scoops.

These abundant, over-the-top monuments are so widely scattered that they define the entire compact capital cityscape, often leading to jokes about whether there are more statues than residents.

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

Milan's duomo is covered in beautiful carving including a curious "dinosaur-like" beast.

This historic covered bridge contains a series of macabre paintings that communicate one thing: everyone dies.

This memorial commemorating fallen Swiss Guards of the French Revolution has been called the saddest stone in the world.

Late at night, the bust of the "Dracula" actor was snuck onto the facade of this Budapest castle.

This Hungarian castle was built out of cardboard and wood until it proved so popular that it got upgraded to stone.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

A work of art that pays homage to a Victorian timepiece in Providence.