<Tr> <Th_colspan="2"> Construction </Th> </Tr> <Tr> <Th> Construction start </Th> <Td> 1801 </Td> </Tr> <P> Saint Catherine Street (officially in French: rue Sainte - Catherine) (11.5 km or 7.1 mi) is the primary commercial artery of Downtown Montreal, Quebec, Canada . It crosses the central business district from west to east, beginning at the corner of Claremont Avenue and de Maisonneuve Boulevard in the city of Westmount, traversing the borough of Ville - Marie, and ending on Notre - Dame Street just east of Viau Street in the borough of Mercier--Hochelaga - Maisonneuve . </P> <P> The street runs parallel to the largest segments of Montreal's underground city . The series of interconnected office tower basements and shopping complexes that make up this main thoroughfare lie immediately north of the street . </P>

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