I've seen all sorts of tour options for the Colosseum, but since I have the handy dandy Rick Steves' audio tour, I was thinking of just reserving a general admission ticket. What areas of the Colosseum does that give me access to? I understand there is an underground, the floor level (is that the same as first level?), second level, and third level.
If I get the gen. admission ticket, will I be missing out on anything really great? Guided tours are already booked from the online site, so my only other option is a tour company which would cost us (me and my 19 yr. old daughter) at least 105 euros.