Gravina in Puglia actually has little to offer, other than the spectacular Palazzo Sottile Meninni. A great small church right by this hotel (the one with the skulls and crossbones). Pay the 3 euros and go in with a guide. The Sotterranea tour really just took us downstairs for a little bit and explained about the caves. (Not for the claustrophobic.) The real place to do this is in Matera, which is a much bigger cave city with many more interesting things to see. Skip this tour. Nice young lady tour guide, but not really worth doing this.