The landscape is relatively flat with river floodplains and grasslands with eucalyptus trees along with rocky areas and patches of rainforest, and in western Arnhem Land a high rugged sandstone plateau cut through with gorges, much of which is in Kakadu National Park. The rivers that form the wetlands include the South and East Alligator Rivers, Mary River, and the Glyde River. The climate is tropical monsoon with a wet and dry season, bringing the highest rainfall in northern Australia (over per year). Temperatures do not fluctuate widely throughout the year.