El Santuari

Descend the mooring line to the walkway level at 13 meters. Swim the length of the structure along the upper corridors — this conserves air at the shallower depth. At the far end, drop down the last column to the sand at 26 meters, where the greatest biodiversity concentrates. Work back along the bottom level, searching the base columns and net remnants for seahorses, scorpionfish, and morays. Ascend to the walkways for off-gassing and the return. In good visibility the entire 50-meter structure is visible from above — in poor visibility the bottom vanishes and the dive becomes atmospheric.

A failed fish farm that the Mediterranean turned into one of the richest artificial reefs on this coast. The structure creates two distinct ecosystems: a sunlit upper level colonised by algae, sea squirts, and clouds of damselfish, and a darker lower level where gorgonians, bryozoans, and false coral grow on the ironwork. The resident seahorse colony — first documented in 2018, with individuals in yellow, red, brown, and white — has made El Santuari a destination for underwater photographers from across the Barcelona diving community. In summer, barracuda and amberjack hunt sardine schools through the open water around the structure.

Old aquaculture nets still hang from the structure — entanglement is a real hazard. Carry a cutting tool and wear gloves for the rusty metal. On the walkway level, juvenile scorpionfish hide in plain sight. An experienced guide from Posidonia Dive will know where the seahorses are currently settled — allow dedicated time if macro photography is your goal. Night diving here is specifically recommended: the fauna transforms completely after dark.