The major thing we wanted to do in Paris was visit the catacombs, an underground ossuary containing…read morethe bones of more than six million people. The catacombs are part of Paris' abandoned mine and quarry network, and bones were moved to the catacombs because the cemeteries were running out of space. The first bones were transferred from the Cimetière des Saints-Innocents after the cemetery was closed in 1780 due to overuse.
The catacombs are an extremely popular attraction, and purchasing tickets in advance is highly recommended as a limited number of people are admitted each hour, and with good reason -- the experience would be extremely unpleasant if overly crowded. However, you can only purchase tickets one week in advance, and the catacombs are not open on Mondays. The two full days we were in Paris were Sunday and Monday, so I had to ensure that we were able to get tickets for Sunday April 7. Fortunately I was successful! Tickets were €29 each, although per the website, they are now €31. Unfortunately, the catacombs are not accessible for people in wheelchairs or who have mobility issues -- the 1.5km long route has 243 stairs -- 131 to descend and 112 to ascend.
We thoroughly enjoyed our visit, and if you want to see bones and skulls (no full skeletons, though), the Paris catacombs won't disappoint!
[Yelp collections: Europe 2024; Paris, France; Beware of stairs!]