Hypogeum of San Salvatore is a prehistoric underground sanctuary - a hypogeum. On the lastered walls are still visible pagan images : Venus, Mars, Pegasus, Persephone, Nymphs, Hercules fighting the Nemean lion and some other. There are Christian symbols as peacock or fish.
See:
- http://www.tharros.info/ViewSites.php?cat=114&lng=en
- Donati,A. and R. Zucca . L'ipogeo di San Salvatore, Sassari 1992