A treasure trove of Renaissance-era funerary art in a Roman church built on top of Nero's grave.

A Nesting Doll of Churches.

The martyr's wax-enhanced skeletal remains lie preserved in a glass case in the Santa Maria della Vittoria in Rome.

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

Jesus' footprints and the first catacombs in the world.

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

2300-year-old Roman road connecting the empire.

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

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

How did a French journalist’s grave become the sexiest statue in the cemetery?

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

France's most famous cemetery, with some of its most curious tombs.

This lesser-known Frank Gehry building houses a treasure trove of cinema history.

The tradition of open-air secondhand and antiquarian bookselling in Paris dates back to the Renaissance.

The final resting place of the "father of special effects."

A multi-storied adobe complex has been inhabited for more than a thousand years.

Seller of surplus nuclear research materials.

Center filled with hands-on displays served as a tribute to several astronauts with connections to the state.

Largest magic museum in the United States with more than half a million pieces of memorabilia.

Former self-sufficient mental institution now a planned community.

The fifth-longest suspension bridge the world, connecting one Michigan peninsula to another.

One of the largest crucifixes in the world stands 55 feet tall in a secluded, wooded area of northern Michigan.

Unique Michigan homes look like something out of Tolkien's "The Lord of the Rings."

Island where motor vehicles are banned -- home to the only carless highway in the United States.