A large flock of birds hover over the birds-viewing garden on the wetland at the estuary of the Yalu River, bordering on China and the Democratic People's Republic of Korea (DPRK), as the 5th International Birds Viewing Festival on the Estuary Wetland of Yalu River opens and attracts over 1,000 ornithologic enthusiasts from both home and abroad to take part in, at this National Nature Reserve in Dandong City, northeast China's Liaoning Province, April 28, 2010. Covering a total area of approximate 100,000 ha, this National Nature Reserve on the Estuary Wetland of Yalu River in Dandong is the country's best-preserved littoral wetland reserve that accomodates more than 1 million birds for overwintering, migration and inhabitation every year. [Xinhua]