Greece has opened its first underwater museum off the coast of the Alonnisos island in the Aegean Sea. It's a new hot spot for diving, offering watery views of a 5th-century shipwreck and ancient wine vessels. The site is located off a tiny outcrop off the Aegean island of Alonnisos, where a wooden vessel sank in the late 5th century B.C., taking with it thousands of amphorae, pointy-bottomed clay jugs used for commerce across the ancient Mediterranean. More wrecks have been discovered in the area -- the middle of the country's largest marine reserve -- holding out the prospect that more such museums will open. Due to the depth and technical difficulty of the descent, only qualified divers are allowed to visit the wreck of a ship that was delivering wine and other goods when it foundered, around the fifth century BC. More than 4,000 two-handled amphorae are anchored in the sand, their positions marking out the outline of the wooden vessel, the remains of which have been washed away over time. "We want to propose another kind of tourism to the people who come. I don't want intensive tourism we can find anywhere else," Alonissos Mayor Petros Vafinis said. With four other wrecks discovered nearby, the goal is that they will in turn become accessible, adding Alonissos to the must-do list for divers around the world.