20 Historic tombs that are still architectural marvels

The Catacombs of Paris are not a royal tomb, which makes them even more unsettling. Beneath the city, former stone quarries were transformed into an ossuary holding the remains of more than six million people after Paris’s cemeteries overflowed. Bones line the walls in careful arrangements, turning a public health crisis into a macabre urban order. Above ground: cafés, traffic, fashion. Below ground: everyone’s reminder to stay humble.