Less famous, but we found SArdinia fascinating archaelogically, and DS, 6 loved it.
there are many very well preserved pre-historic sites called 'Nuraghi' or something. Also well temples, buildings and barrows (live Avebury, a bit) that you can go into (some are very tall, cone shaped buildings built entirely rom small boulders - and have bats nesting in them) We went to Santa Cristina - on the list of the following link - and another famous and huge pre-historic settlement.
Also, a couple of beautiful towns with excellent museums - with an excavated grave in one - AND the fabulous Phoenician-Roman ruined city at Thassos. Also Tiscali, the castle at Cagliari.
It's a lovely country, fantastic scenery - we went in October and it was very warm, we could swim in the sea. We stayed in a cheap rented villa on the West coast at the Northern end of the Costa Verde.
I loved Sardinia - and it seemed not wildly expensive. Coastal resorts were very 'closed for the winter' while little inland towns were buzzing with brilliant cheap local restaurants, and beautiful streets.
some examples of Sardinian archaelogical sites