Regional Municipality of York in the context of "Name of Toronto"

Markham (/ˈmɑːrkəm/) is a city in York Region, Ontario, Canada. It is approximately 30 km (19 mi) northeast of Downtown Toronto. In the 2021 Census, Markham had a population of 338,503, which ranked it the largest in York Region, fourth largest in the Greater Toronto Area (GTA), and 16th largest in Canada.

The city gained its name from the first Lieutenant-Governor of Upper Canada, John Graves Simcoe (in office 1791–1796), who named the area after his friend, William Markham, the Archbishop of York from 1776 to 1807.

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.

The Greater Toronto Area, commonly referred to as the GTA, includes the city of Toronto and the regional municipalities of Durham, Halton, Peel, and York. In total, the region contains 25 urban, suburban, and rural municipalities. The Greater Toronto Area begins in Burlington in Halton Region to the west, and extends along Lake Ontario past downtown Toronto eastward to Clarington in Durham Region.

According to the 2021 census, the Census Metropolitan Area (CMA) of Toronto has a total population of 6.202 million residents, making it the nation's largest, and the 7th-largest in North America. However, the Greater Toronto Area, which is an economic area defined by the Government of Ontario, includes communities that are not included in the CMA, as defined by Statistics Canada. Extrapolating the data for all 25 communities in the Greater Toronto Area from the 2021 Census, the total population for the economic region included 6,711,985 people.

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.

Steeles Avenue is an east–west street that stretches 77.5 km (48.2 mi) across the western and central Greater Toronto Area in Ontario, Canada. Running from Appleby Line in Milton in the west to the Scarborough-Pickering Townline in the east, where it continues east into Durham Region as Taunton Road, which itself extends 58 km (36 mi) across the length of Durham Region to its boundary with Northumberland County. It is most notable for being the north city limit of Toronto where it borders the southern limit of York Region along its eastern half.

York Region refers to Steeles Avenue as York Regional Road 95 but this use is only internal and there are no signs posted; as the street borders and is maintained by the City of Toronto. Through Peel and Halton Regions, the road is signed as Peel Regional Road 15 and Halton Regional road 8, respectively.

Vaughan (/vɑːn/ vawn) (2021 population 323,103) is a city in Ontario, Canada. It is located in the Regional Municipality of York, just north of Toronto. Vaughan was the fastest-growing municipality in Canada between 1996 and 2006 with its population increasing by 80.2% during this time period and having nearly doubled in population since 1991. In 2021, the population of Vaughan was 323,103. It is the fifth-largest city in the Greater Toronto Area, and the 17th-largest city in Canada.

Black Creek is a river in the Golden Horseshoe region of Ontario, Canada. It flows from the city of Vaughan in the Regional Municipality of York to the Humber River in Toronto. Black Creek is smaller than most of the waterways in the Greater Toronto Area.