Old Danube

The Old Danube is an oxbow lake in Vienna, a quiet arm of the Danube separated from the main river. It lies northeast of the New Danube, once part of the river’s wild floodplain before engineers reshaped the landscape in the 19th century. The lake covers about 1.6 square kilometres and is fed mainly by groundwater, its waters calm and shallow. In the early 18th century it carried the Danube’s main flow, but after floods and regulation work it became a still inland water. The lake’s banks once hosted ship mills and the first Austrian steamboat, the Franz I, while early seaplanes were tested above its surface. The Old Danube supports a rich ecosystem with more than twenty kinds of fish, including wels catfish, pike and zander. Protected waterbirds such as cormorants glide above the reeds, and European beavers have returned to the area. Conservation efforts have brought back rare plants like yellow irises and pond lilies, while reedbeds shelter around forty-five plant species. The lake’s clear waters and varied habitats make it an important green space within the city. Its ecological recovery shows how urban waters can be restored when managed with care. Visitors find a long stretch of public beaches and piers along the eastern shore, where rowing clubs and small restaurants line the water. Rowing boats, pedalos and electric boats can be hired, and the lake is popular with beginner sailors. In summer, regattas such as the Vienna Nightrow draw crews to the water, while winter skaters cautiously test the ice when conditions allow. The lake is easily reached by underground train, yet it feels remote, framed by high-rise buildings yet shielded by its own green banks. Locals swim at spots like Gänsehäufel and the Bundesbad Alte Donau, enjoying a stretch of nature close to the city centre.