The Blue Grotto is a chain of seven sea caves under a limestone arch thirty metres high on the south coast of Malta, near the village of Żurrieq, whose vaults are lit blue by sunlight bouncing off the pale seabed, and they are entered in open wooden boats of eight or ten people from the slipway of the inlet of Wied iż-Żurrieq, in a trip of twenty minutes that runs from April to September, when the sun stands high enough to drive the light through the water. The arch stands free of the cliff, and the boats motor under it and into the caves behind, where the water goes from deep blue to a burning electric turquoise over the white floor and the walls shine with orange and purple minerals; the sea did not do all the work, since the caves were widened by hand in places for the boats. A pull-off on the road above the cove puts the viewer outside the arch rather than under it, so that the whole span reads at once with the boats passing beneath for scale, and from it the flat islet of Filfla lies on the horizon, a bird reserve that spent eighty years as a naval gunnery target.
The inlet at Wied iż-Żurrieq is the other half of the visit. The narrow cove below the viewpoint is deep, clear water with cliffs on both sides, and through the summer Maltese families take over the flat rocks around the slipway, swimming off the ladders while the boats go in and out; from the same cove divers walk in and swim out to the Um El Faroud, a tanker of 110 metres scuttled in 1998 and lying upright on the sand at 36 metres, one of the best wreck dives in the Mediterranean. The cliffs of the coast run east to the temples of Ħaġar Qim on the headland above, older than the pyramids. The Blue Grotto is a cave lit from the floor, and the boat goes in when the sun is high.