In the channel separating La Maddalena from the mainland, next to the shore several granite rocks emerge from the water, and one of them is characterized by the presence of a warning pillar for seagoing staff. Around it, a granite seabed slopes down, covered with big blocks forming ravines, channels, and deep fissures. The bottom reaches the 25m, but you can enjoy the site already from the first meters of depth for the extraordinary biodiversity characterizing it.
The seaweed formation covering the rocks houses pronged yellow formations of Gold Sponge (Aplysina aerophoba), a protected sponge which is replaced in the shady area by the Yellow cave Sponge (Aplysina cavernicola).
The ravines and the fissures between the rocks favor and accelerate the passage of the currents which provide food to a great number of organisms filtering water: they are mainly sponges, bryozoans, and ascidians, with the Yellow Cluster Anemone forming a lively yellow background, sometimes interrupted by red gorgonians. Shoals of Common two-banded Seabreams find shelter under the granite vaults, while in the detritus areas the local Caulerpa prolifera grows.