I usually start the dive with no more than a glance at the entrance of the Grotta delle Catene (Chains Cave) (-25 mt) where I fixed a plastic danger signal because It's nar­row and the bottom Is muddy. On the walls we can see the remains of the two chains fixed in the seventies by Club Mediterranee because some accidents occurred. The bot­tom Is a carpet of peacock worms Sabella pemcillus not to be confused with spiro­graphs Sabella spallanzanii. We swim toward the entrance of the Cathedral whose vault Is at -3 mt and the bottom at - 16 mt. After fifteen meters we turn to look at the big rocky arch against the blue light. We can reach the same panoramic point passing through a tunnel with a narrow entrance. Inside we find the boxer shrimp Stenopus spinosus and the cave spider crab Herbstio conc1yhctc.The dive continues at very low depth to surface n four inner lakes. Through a mullioned win­dow we enter the "poche d'air", where at New Year s Day we have a party. Maximum three at a time, we visit a small room with a scenographic wall. It's possible to meet beau­tiful cowrìes Luna lurida and Erosaria spurca, rare flatworms and nudibranchs molluscs. After a look at a fine window with a small column facing the blue of the entrance, we leave the "poche d'air" to reach some shelters full of small gnats. They are adult mysids or opussum shrimps. The second lake is full of draperies, small columns and helictites (tiny cave formatìons growing like branches against gravity).The carbonate purity determines the white or dark colour. Diving at a maximum depth of two metres we arrive at the turquoise water of the main lake. Very nice view! On the walls the orange star corals Astroides calycularis are smaller than in the Grotta Azzurra. The Cathedral Is a dosed structure with less water change that means less food transport and growth. After 55 minutes wc defnitively surface. As we spent half of the dive at sea level, our digital Instruments sign less time and our pressure gauge Is far from the reserve Indication.