The Lobau is a Vienna floodplain on the northern side of the Danube and partly in Großenzersdorf, Lower Austria. It has been part of the Danube-Auen National Park since 1996 and has been a protected area since 1978. It is used as a recreational area and is known as a site of nudism. There is also an oil harbour, and the Austrian Army uses the Lobau as a training ground.