My husband and I are currently in Florence. We arrived a little late at the Mercato Centrale and didn't get to spend as much time there as we would have liked. We are traveling to Rome next. Is Campo di Fiori an indoor market like Mercato Centrale? Or is there another market that is more similar to Mercato Centrale? Thanks!
The foodie market of Rome is the Testaccio market. Amazing produce, meats, fish and the like! Also, while in Testaccio, go here: http://www.volpetti.com/.
To answer one of your questions, the Campo de' Fiori is an outdoor market.
There is a Mercato also in via Catania, near the Policlinico hospital of the Univ. of Rome. It's in one of the fascist era buildings near the University. The most famous outdoor flea market in Rome is Porta Portese, in the Trastevere district near the Sublicio bridge.