Some (well, a lot) special openings on the 25th December 2011 and the 1st of January 2012, when many museums and archaeological sites across Italy will be open, free of charge.
The list is a long one – see it here – but perhaps the most significant venue is the Colosseum in Rome which will be open from 09.30 until 15.30 both days, entrance free of charge.
Italy ticket booking