Thousands of limestone islands in an emerald sea
Ha Long Bay is one of Asia's great natural sights: nearly two thousand limestone towers and islands, many topped with jungle, rising from calm green water in the Gulf of Tonkin. It is a UNESCO World Heritage Site, and most visitors see it from a cruise boat, ideally staying overnight to wake among the karsts. Trips stop at caves such as Sung Sot, floating fishing villages and quiet beaches, with kayaking between the islands. Neighbouring Lan Ha Bay and Bai Tu Long Bay are quieter alternatives.