Hidden beneath the famous St. Peter's Basilica is a veritable city of the dead that may hold the remains of St. Peter himself.

Breathtaking and huge 430 year old maps of Italy.

Rome's semi-secret peephole vista is also a former Crusader stronghold.

The Vatican's secret porn-festooned bathroom was painted in erotic murals by one of the greatest artists of the Renaissance.

Semi-mystical manmade towers of rocks decorate this rocky seaside.

Gaze upon chocolate sculptures depicting everything from chariot races to Gaudí's famous church at this shrine to sweets.

Mountain where Jesus was first tempted by the Devil.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

These secluded and abandoned anti-aircraft defenses have become one the most scenic viewpoints in Barcelona.

Museum celebrating the ocean, with the largest wunderkammer dedicated to sea exploration.

The once forbidden "secret cabinet" of erotic art from excavations of Pompeii and Herculaneum.

The glowing blue Nymphaeum of Emperor Tiberius.

In Egypt's expanding metro area, many of the neighbors are dead.

Hundreds of thousands of ancient documents offer a unique glimpse into Jewish life in Cairo.

Egyptian treasure trove of fossils documenting the whale's transition from land mammal to sea creature.

God's Saharan sandbox of wrath.

One of the most spectacular canyons in the world.

Traditional 11th-century outdoor tannery.

Crumbling necropolis set high above Fez.

World's largest film studio, where visitors tour the decaying sets that litter the harsh desert environment.

Mosaics, storks, and brothels—this ancient city has it all.

A fortified city, home to a remaining population of five families

Morocco's largest Jewish cemetery.

Numerous impressive carvings are embedded in the trees lining this street in Marrakech.