Zawadowskie Islands Reserve - fauna conservation reserve which consists of islands and shoals located on the Vistula River near Kępa Zawadowska and Błota, in the districts Wawer and Wilanów. The total area of the reserve is 803 hectares and the area of Warsaw includes 88.26 ha of the reserve. Scientists believe the reserve is the Europe's largest habitat for endangered little terns and refuge for otters and beavers, there are also unique breeding grounds of plovers. The reserve is threatened by the degradation through landfill of ash from CHP Siekierki located nearby on Kępa Zawadowska.