Sardinia. Public Domain.

Sardinia is much older than the italian Peninsula. Its structure is complex and quite differentiated. It has areas of granite, of volcanic rocks and large karst areas.

The north and the south-east is built on granites, forming a unique landscape with strange rock formations. The west is volcanic with basalt and other volcanic rocks. The east is covered with slate and calcareous sediments. The south-west is famous for its resources like coal and lead and tin ores. They were mined two thousand years ago by Romans and Phoenicians.

The island has numerous karst areas, currently 4,000 caves are known. We have listed 12 show caves, but the official number is 9. We guess it depends on how you define the term show cave.