The Blue Grotto is one of the treasures of the southern coast. You can reach the site by boat, leaving from the little port of Wied iz-Żurrieq. The idyllic site is perfect for swimming and diving. Inside the grotto, the side of the cliff drops down to a depth of some 50m. It is at its best early in the morning on a sunny day, when the sun is still low enough to illuminate the marine depths. The view is even more spectacular when the sea is calm.