I'm a sucker for history and hidden things in a city. We like to see the big sights, but we also take great joy in exploring the lesser known parts of cities when we travel. One of the things I really wanted to do with our time in Paris was make a visit to the catacombs. While not secret by any means, climbing underground for a few hours, exploring tunnels bored hundreds of years ago and now filled with bones, definitely has the air of feeling secret, hidden, and definitely eerie (what can be more hidden than something underground with limited access?!). The catacombs were the first stop of many on our days of sightseeing in Paris.