Caves can form naturally underground or under water, and contain important fossils. Some famous caves include Dragon's Lair cave in Europe, known for cave bear fossils from 50,000 years ago, and the Blue Grotto on Capri Island, Italy. Caving or spelunking is the exploration of caves as a sport, with clubs exploring caves around the world using equipment like headlamps, helmets, and boots. Cave diving also involves underwater exploration with specialized equipment in caves under water. Basic safety tips for exploring caves include never going alone, bringing multiple light sources, wearing protective gear, and informing others of your plans.