Designated a UNESCO World Heritage Site, the magnificent Halong Bay is spread across a 580 sq mile (1,500 sq km) area, with more than 2,000 pinnacle-shaped lime stone and dolomite outcrops scattered across it. According to legend, the bay was formed when a gigantic dragon – ha long means descend ing dragon – plunged into the Gulf of Tonkin, and creat ed the myriad islets by lashing its tail. Geolo gists have explained that the karst topo gra phy is the prod uct of  selective erosion over the millennia. The result is a labyrin- thine seascape of bizarrely shaped outcrops, iso lated caves,  and sandy coves