What a wicked place! It’s not filled to the brim with tourists which is a very refreshing change.
The place has history, it’s spectacular, I recommend take you time, and place DON’T TAKE PICTURES. Respect the graves!
The walls are damp and chilling, it’s fun to go with a group, walk slowly, soak it all in, and read all the information at the beginning before you actually enter the real catacombs.

Enjoy!