Pierrefonds-Senneville is a former Montreal borough in the West Island area of Montreal, Quebec. It was formed by forced merger on January 1, 2002. After Senneville voted on June 20, 2004 to demerge from Montreal and returned to being an independent municipality on January 1, 2006, the Pierrefonds sector was merged with Roxboro to create the borough of Pierrefonds-Roxboro. See also List of former boroughs Montreal Merger Municipal reorganization in Quebec Pierrefonds-Roxboro Former Montreal boroughs Populated places established in 2002 2006 disestablishments in Quebec 2002 establishments in Quebec fr:Pierrefonds-Senneville