Lake Neusiedl (), or Fertő (; ; ; ; ) is the largest endorheic lake in Central Europe, straddling the Austrian–Hungarian border. The lake covers , of which is on the Austrian side and on the Hungarian side. The lake's drainage basin has an area of about . From north to south, the lake is about long, and it is between and wide from east to west. On average, the lake's surface is above the Adriatic Sea and the lake is no more than deep. Water level fluctuations In the past, rainfall and aridity caused significant floods (which in 1768 enlarged the lake to its maximum documented size of ) and significant decreases in the lake's level, although frequently there seemed to be no apparent connection with the weather situation. Stratigraphy shows that the lake bed has totally dried up at least 100 times since its formation (18,000–14,000 BC). During recent history the lake's complete disappearance has been documented in considerable detail on several occasions, e.g. in 1740–1742, 1811–1813, and most recently in 1866, when the private diary of a local, Gottlieb Wenzel, noted that he crossed the bed of the lake on 4 June without soiling his boots. Parts of the lake bed were claimed for agriculture; wheat and turnips were being planted. However, in 1871 the lake began to return and by the spring of 1876 it had already reassumed its usual size. The last (brief and partial) vanishing took place during the summer of 1949 when the northern part of the lake bed (to the approximate latitude of Podersdorf) fell dry for a few weeks. Each time the drying-up of the lake bed caused major environmental disruptions because the humidifying and temperature buffering effect of the large water body was absent, and because the winds blew large amounts of salty dust into the surrounding villages. On earlier occasions the lake was sometimes referred to as a "swamp", suggesting a very low water level with an expansion of reeds throughout the lake bed. Two records dated to 1318 and 1324, respectively mention a "river", implying that at this time the lake might have been reduced to a central body of water running from north to south. Today the water level is controlled by an artificial outflow, the , and a sluice on Hungarian territory near Fertőújlak, and bilateral issues are dealt with by the Austro-Hungarian water commission which