One of several skulls claiming to belong to the beheaded St. John the Baptist is on display at this Roman church.

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

The final resting place of the poets Shelley and Keats.

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

This hill made entirely of ancient Roman jars was simply a garbage dump to the people of the time.

The mummified relic of St. Antoninus.

Over 50 exquisite hand-painted Renaissance maps decorate a Medici storage room.

The famous sculptor left his mark on this Italian wall in an internationally protected example of street art.

The doodles of a genius line the walls of a secret room under the Medici Chapel, where they were hidden for nearly 500 years.

Diego Rivera's massive tiled fountain and failed infrastructure project.

A jaw-dropping "megalibrary" that turns book-browsing into a geometric adventure.

This Aztec structure remained hidden until the demolition of a supermarket exposed the lost temple.

A close look at the church's walls reveals pieces of Mexico's history.

Gilded heaven for philatelists and architecture freaks, still in full working order despite sitting atop tremulous ground.

Diego Rivera hid various people and symbols in his first large-scale mural project.

A disquieting Aztec sculpture displays hundreds of stone skulls representing the victims of human sacrifice.

These subterranean models show Mexico City's central square during three different eras.

These haunting ruins of a 700-year-old Prehispanic city have witnessed centuries of wars and massacres.

The former headquarters of history's oldest megacorporation.

Each time a baby is born in Ghent, these streetlights flash in silent celebration.

Drink among marionettes at this pub inside a historic puppet theater.

A wonderfully kitsch bookstore the size of a supermarket.

Brussels' favorite peeing boy has a sister.

Potato-peeling mannequins, Inca art, and a dangling tuber mobile help trace the history of fries at this Belgian museum.