Asian shipwrecks: Trade routes map
For more than 2,000 years ships have travelled along the maritime silk road from Europe and the Middle East right up to China and back again, trading spices, silks, tea and ceramics.
Vessels would hug the 3,000km (1,864-mile) coast of Vietnam on their way to and from China. The journey could be perilous, particularly when storms hit. Wrecks of thousands of ships that ran into trouble are thought to lie at the bottom of the sea - attracting divers and treasure hunters.
Ceramics and wrecks found in key areas across south and south-east Asia hint at a vibrant trade in ceramics. Many archaeologists believe this route should by rights be called the Ceramic Road.
Discoveries still being made show that for centuries before Europeans colonised parts of Africa and southern Asia, societies interacted, linking people across continents and oceans. The precise nature of this maritime world is still being researched by scholars.