by Cham people about 3,000 years ago. However, business contacts were established with other countries about 1,000 years ago. The Cham islands were used for transhipment to the mainland by the Cham. Many architectural monuments dated to the 18th and 20th century are reported, which include the Than Yen Sao shrine built in 1843 at Bai Huong, and the Hai Tang Pagodas built in 1753 on the western hillside of Hon Lao. Small monuments, dikes, and basins to grow rice on terraces are also seen in the interior forest areas. Resources The rich aquatic resources of the islands consist of of coral and of seaweeds. 135 species of coral, four species of tiger shrimp and 84 species of mollusc are also found in the waters surrounding the islands; some of these species are listed in the Vietnam's and the World's Red Book of Endangered Species. Medicinal plants have also been inventoried on the islands. The traditional resources of the Cham people of the islands comprise rice farming, fishing, trading in pepper, cinnamon bark, ivory and wood with neighbouring countries, accessed through the port of Hoi An. The islands are known for the Salanganes swallows whose nests have been a source of revenue to the local people. The expensive Chinese dish of bird's nest soup is made out of these nests. Thus, swallow nest harvesting has become an important industry in the islands, which also provides revenue to the state. The annual swallow harvest is reported to be about 1.4 tons, valued at US$4,000 per kilogram. Gallery References References Hardy, Andrew (2009): "Eaglewood and the Economic History of Champa and Central Vietnam" in Hardy, Andrew et al.: Champa and the Archeology of My Son (Vietnam). NUS Press, Singapore External links Coordinates of Cham Islands Travel guide to Cham Islands Information about Cham Islands Landforms of Quảng Nam province Islands of Vietnam Biosphere reserves of Vietnam