Île-des-Soeurs, or Nuns' Island, about 5 km from the heart of downtown Montreal.
About 20,000 people, 3.75 sq. km.
It's a fairly posh but modern area with nice high-rise condos and other forms of lower-rise housing types.
https://www.google.com/search?q=ile+...A_enCA931CA931
Part of the city proper.