Charco Azul is one of La Palma's best natural swimming spots, a set of lava-rock pools on the north coast where the Atlantic is tamed just enough for a safe, beautiful dip. The water can be startlingly clear, with black rock and green slopes giving the place a strong island character.
Go when the sea is calm and avoid treating it like a beach resort. It is more rewarding as a short coastal stop: swim, dry off on the rocks, and continue exploring the greener northern side of La Palma.