Paris, France (CNN) — Beneath the streets of the City of Light lies a world draped in darkness and shrouded in silence. The tunnels are narrow, the ceilings are low and death is on display. The skulls and bones lining the walls, arranged in a macabre fashion, make up what is known as the Empire of the Dead — the Catacombs of Paris. The catacombs snake below the city, a 321-kilometer (200-mile) network of old quarries, caves and tunnels. Some Parisians are drawn to this largely uncharted territory — a hidden network of adventure, discovery and even relaxation. They are known as ‘cataphiles’ and the catacombs are their playground. It…