One of the three principal islands of the Maltese archipelago, the island of Malta is the largest of the chain. Its capital Valletta, a lively, bustling city with many buildings dating back to the 16th century, teems with cathedrals, palaces and forts. The impressive Grand Harbour offers a dramatic arrival. The top archaeological attraction is the UNESCO-designated Hypogeum temple ruins, a macabre, 5400-square-foot underground necropolis and the world's only underground prehistoric temple.