Aurora, Ontario in the context of "Oak Ridges Moraine"

The Humber River (Ojibwe: Gabekanaang-ziibi, lit. 'river at the end of the trail') is a river in Southern Ontario, Canada. It is in the Great Lakes Basin, is a tributary of Lake Ontario and is one of two major rivers on either side of the city of Toronto, the other being the Don River to the east. It was designated a Canadian Heritage River on September 24, 1999.

The Humber collects from about 750 creeks and tributaries in a fan-shaped area north of Toronto that encompasses portions of Dufferin County, the Regional Municipality of Peel, Simcoe County, and the Regional Municipality of York. The main branch runs for about 100 kilometres (60 mi) from the Niagara Escarpment in the northwest, while another major branch, known as the East Humber River, starts at Lake St. George in the Oak Ridges Moraine near Aurora to the northeast. They join north of Toronto and then flow in a generally southeasterly direction into Lake Ontario at what was once the far western portions of the city. The river mouth is flanked by Sir Casimir Gzowski Park and Humber Bay Park East.

Richmond Hill (2021 population: 202,022) is a city in south-central York Region, Ontario, Canada. Part of the Greater Toronto Area, it is the York Region's third most populous municipality and the 27th most populous municipality in Canada. Richmond Hill is situated between the cities of Markham and Vaughan, north of Thornhill, and south of Aurora.

Richmond Hill has seen significant population growth since the 1990s. It became a city in 2019 after being a town since 1957. The city is home to the David Dunlap Observatory telescope, the largest telescope in Canada.

The Holland River is a river in Ontario, Canada, that drains the Holland River watershed into Cook's Bay, the southern extremity of Lake Simcoe. The river flows generally north, and its headwaters lie in the Oak Ridges Moraine. The Holland River watershed is approximately 600 square kilometres (230 mi), spanning an area that includes New Tecumseth, King Township, Newmarket, Aurora, East Gwillimbury, and Whitchurch-Stouffville. The river's watershed also contains the Holland Marsh, a fertile farmland region renowned for its vegetable production.

The river was originally known as Micicaquean Creek, its indigenous name. It was renamed by Lieutenant-Governor Simcoe after Captain Samuel (Johannes) Holland, (1729–1801), Dutch-born first Surveyor General of British North America.