Cova dels Arcs

Three natural arches open ahead as you enter, daylight still visible through the water rippling above. The standard recreational route runs about 60 minutes, crossing the main chamber lit by filtered sun from outside before exiting to open water over the rocky seabed of Cala del Moraig, where octopus, moray eels and conger eels shelter in the crevices. Snorkellers get much the same view from the surface, best attempted early morning when the sea sits calmest and the light through the arches is strongest. One chamber near the entrance is even reachable on foot down steps from the cove, letting non-divers see the arches without getting wet at all.

The arches themselves formed around 60,000 years ago, when sea level sat 120-130m lower and these galleries were dry, walkable passages later flooded as the sea rose. That's a genuinely rare thing to swim through, and it's the reason the chamber is a visual draw rather than just another rock overhang. Past the natural-light boundary, the same karst system continues as a fully submerged river system that a dedicated team of Spanish cave divers has mapped past 3km from the sea mouth as of a 2025 expedition, working alongside university researchers studying the cave's biology. That work belongs to a different diving discipline entirely, not a next step from the dive described here: the system has taken lives over its decades of exploration, and centres treat the natural-light boundary as the hard line between a recreational cavern and a committing technical cave.

Reserve your spot at calamoraig.es before a summer visit, and expect to pay for parking; arriving before 9am gets you the calmest water and best light. Water shoes matter on the entrance rock, which is slippery underfoot. A local guide is worth having if you haven't dived a cavern before, and diving within sight of the exit and the daylight above it is the one rule that keeps this an easy, guided dive rather than something else altogether.