Salt-encrusted remains of a dead saltbush on the surface of Lake Eyre South, a salina in the Lake Eyre Basin, a vast internal drainage depression below sea level in northern South Australia. Vestige of an ancient inland sea long since dried up, Lake Eyre does fill infrequently from floodwaters, when the inland sea temporarily springs to life. It then evaporates under the desert sun, leaving salts which inhibit even halophytic vegetation.