We visited the Museo Nazionale Romano - Palazzo Massimo alle Terme in October 2013.
Pros: Excellent displayed museum, maybe the best in Rome in my opinion. The sculpture collection is really breathtaking, especially the Greek Boxer at Rest, the Discobulus and, of course, my favourite, the Sarcophagus of Portonaccio - an awesome piece of art that is worth the whole visit to the museum (seriously, don't miss it. If you don't believe me, just google it).
The mosaics and frescos in the upper floor were impressive too, and they even have a painted room that changes its lights (morning, afternoon, evening) for the visitor to imagine the different moments of the day.
There's a wonderful numismatic collection in the basement that covers much of Roman history, and also a bonus point: they have a magnificently preserved mummy of a Roman girl (the Grottarossa mummy), displayed with great respect and lots of interesting information regarding the conservation and the studies they've done on her.
The museum was almost empty, so we had it practically to ourselves. It was a nice change, having visited the crowed Musei Capitolini the day before, but we didn't understand why it isn't much popular. It was one of the finest museums I've ever been to.
Everything is accessible for wheelchairs and they have two big lifts. There are lots of chairs strategically situated to seat, rest and enjoy the pieces of art, as well as a huge amount of informative panels and videos.
Cons: None. Really.
Practical information and tips: Tickets last for three days, so you can return if you want. Moreover, they're valid for the other Museo Nazionalle sites (Palazzo Altemps, Crypta Balbi and Terme di Diocleziano).
Overall: We just loved it. I would almost say that if you can only visit one museum in Rome, skip the Capitolini and go there. It is well, well worth the visit.
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