Owen Sound is located on the southern shores of Georgian Bay in a valley below the sheer rock cliffs of the Niagara Escarpment. The city is located at the mouths of the Pottawatomi and Sydenham Rivers. It has tree-lined streets, many parks, and tree-covered hillsides and ravines. In 1814-1818, the first Admiralty Survey of Lake Ontario and the coastal waters of Georgian Bay was undertaken by Captain William Fitzwilliam Owen, Royal Naval Officer, surveyor, land-owner, politician, author and justice of the peace. He named the bay and the future site of Owen Sound after his family. His successor, Admiral Henry Wolsey Bayfield, completed the first survey of lakes Erie, Huron, and Superior in 1817-1825. The work of these officers rendered great service to Canada by increasing the safety of navigation. The city was first known as Sydenham when it was settled in 1840 by Charles Rankin. Prior to his arrival, the area was inhabited by the Ojibway people. In 1851 the name was changed to Owen Sound. For much of its history, it was a major port city known as the "Chicago of the North." Owen Sound Bay is a valley in the Niagara Escarpment formed by rivers that cut through the escarpment limestone. The valley begins where the Sydenham River cuts down through the escarpment at Inglis Falls and extends out through the bay beyond Bayview Point for a total distance of 16 kilometres. As the Niagara Escarpment winds its way across southern Ontario, it is interrupted by many deep valleys carved out by the erosive forces of water and ice. Like Colpoy's Bay to the north, Owen Sound Bay is a drowned valley partially hidden under Georgian Bay. Other escarpment valleys like the Dundas Valley are buried under glacial sediments, while the Beaver and Bighead Valleys are occupied by rivers. Today the Niagara Escarpment continues to slowly erode back from its present position.