Which catacombs would you recommend and why? RS book mentions a few and we really only have time to visit 1 site.
From what I've heard they are somewhat similar. We ended up seeing the one that was actually open on the day and time we were able to go. They have different opening days and hours so check carefully which ones you could actually consider.
We prefer San Calixto to San Sebastiano. The former has more amenities.
Buon viaggio,
RB