This former Roman Catholic Church still contains the embalmed hearts and organs of 22 popes.

This ritzy Italian market is built around a statue of an unforgiven heretic who was burned for his belief in an endless universe.

A collection of objects supposedly singed by the hands of souls in purgatory.

A fairy tale castle in modern Rome.

Jesus' footprints and the first catacombs in the world.

The engineering wonder and pleasure dome of a much-maligned emperor still holds undiscovered secrets.

The skull of the patron saint of lovers lies in the Basilica di Santa Maria in Cosmedin—maybe.

At the crypt of St. Mary of Eulogies and the Dead you are left alone to ponder mortality among piles of skulls.

The underground sanctuary of a mysterious ancient cult.

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

This hidden Art Nouveau courtyard is an opulent feast for the eyes.

Architectureal fantasy quarter of Rome.

Hundreds of lucky felines haunt the ruins where Caesar was murdered.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

Bar full of oddities, specimens, artifacts and homages to the great dime museums of the past.

An obscure federal monument honors the French diplomat who served as Ambassador to the U.S. during WWI.

Through the decades, Black music stars have performed at this historic hub for music and the arts.

The 28,000-year-old specimen is remarkably intact.

During Prohibition, the U.S. Congress had an "official" bootlegger, with his own Capitol Hill office.

A muscular Art Deco monument represents the struggle between regulators and unbridled markets.

The world's oldest soul food restaurant is also one of its best.

Amid the sprawling Defense Intelligence Agency Headquarters is one of Washington's least accessible museums.

A gorgeous mural outside a beloved D.C. restaurant pays homage to famous Black Americans.

For 60 years, the academy had no permanent location until members voted Washington D.C. as its forever home.