This 800 metre structure, built in the late 1930's, is one of several isolating the waters of the River Murray from the sea and the Coorong. Visitors can walk out to the centre, where the lock is located, and either view the magnificant lake stretching back up to Goolwa or see the broad estuarine river heading off towards its mouth a few kilometres downstream. Strictly speaking it is not a building but it is so essential to what makes the Lower Murray ticks that it had to be included.