Passage: With permission from the French authorities the film was shot in the real catacombs of Paris. There was very little use of props, as the actors had to use the environment around them. Production in the actual catacombs was difficult for the cast and especially the crew as there was no electricity or cell phone service in the centuries-old tunnels. As Ben Feldman suffered from claustrophobia, he had to keep taking breaks to cope.

Question: Were there many props used during the making of the film?
very little