Birds build nests on vertical cliffs in a cave on Cham Islands. (Photo: Quang Nam Newspaper) Quang Nam (VNS/VNA) - After four years of preparations, the National Office of Intellectual Property of Vietnam has granted Geographical Indication (GI) to the Cham Islands The Hoi An city People’s Committee, which has jurisdiction over the islands, said the product contributed 20 percent to the city’s Gross Regional Domestic Product (GRDP) annually. A report from the Ministry of Science and Technology said the bird's nests are seen as one of the best products in Vietnam due to their high nutritional value with 50 percent protein.