A natural rocky bar across the Yarra River 10 km from its mouth determined the site for the city's foundation and early settlement. The Falls formed a low barrier between the brackish tidal water downstream and the fresh water upstream, furnishing the infant settlement with a potable water supply. Attempts were made in 1839 to dam the Falls using convict labour, and from the early 1840s a more solid dam was constructed to assure the town's water supply. Early punts operated above the Falls, while the saltwater basin or pool below was suitable for shipping to dock and turn. In January 1845 John Charles Batman, son of early settler John Batman, drowned at the Falls while fishing. Located in a line just west of present-day Queen Street, the Falls were finally removed in the 1880s for construction of Queens Bridge.