La Vaca

The boat moors on the sheltered south side of Meda Gran, and you descend to approximately 12 metres where the tunnel entrance opens in the rock face — shaped, according to local lore, like a cow's head. A large grouper typically hovers at the mouth, entirely unfazed after decades of marine reserve protection. The passage runs straight north through the island for 30 metres, roughly 5 metres wide, divided by natural rock pillars into sections. Light enters from three openings, so the tunnel never goes dark — you swim toward the glow of the north exit, which emerges at around 22 metres onto a vertical wall draped in red gorgonian fans. From here, the wall drops to 45 metres for those with the certification and gas to explore it. Most divers work the north face at 20-25 metres, where schools of brown meagre and gilt-head bream gather, before ascending and looping back toward the mooring.

La Vaca is a cavern dive in the strict sense — naturally lit, wide enough to swim side by side, with visible exits throughout — yet it delivers the sensation of passing through solid rock beneath an island. The backlight streaming through the tunnel creates conditions that underwater photographers return for specifically: silhouettes framed against blue water, shafts of light picking out the reds of coral on the walls. The transition from the enclosed tunnel to the open north face is one of the sharpest contrasts on any single dive in the Medes — dark rock and encrusting life giving way to a vertical garden of gorgonians with open sea beyond. On the way back to the boat, the Rincon de la Vaca adds two small caves and a chimney at 13 metres, a brief coda that rounds out a dive with more structural variety than most sites in the archipelago can offer.

Buoyancy control matters inside the tunnel. Silt on the floor reduces visibility quickly if disturbed, and the walls host fragile organisms including red coral — stay mid-water through the passage and avoid contact with the ceiling. If your guide continues onto the north wall, watch your depth: the seabed reaches 45 metres and the gorgonians draw the eye downward. On Nitrox 32%, your MOD becomes the limiting factor before your air does. The site sits on the Punta Galera side of Meda Gran, which provides natural shelter, so conditions inside the tunnel are typically calm even when other Medes sites are current-swept.