<human>:  Where are the Catacombs of Paris?
<bot>: They are located in the city of Paris, France. They were built during the Roman Empire, and they are the largest known underground network of tunnels in the world. The Catacombs of Paris are home to over 200 miles of tunnels. They were used as a place of refuge during times of war, and they also served as a burial site for people who died in the city.