BMO Field (wikipedia entry stadium guide page)
Toronto, Ontario (google maps)
Canada's newest stadium, BMO Field has yet to host a match. Its first action will be the home opener for Toronto FC of MLS on April 28th. It is a 20,000 seat stadium and, unlike the fields in Burnaby, Victoria and Edmonton, will feature a FieldTurf surface. The stadium is owned by the city of Toronto, and is sometimes referred to as the National Soccer Stadium. Canada's first match, against Chile on Canada Day (1 July) will be played in Toronto, and the stadium will host 12 matches in all, including a semi-final matchup and the tournament final. Considered the tournament's showpiece, the stadium's naming rights are owned by the Bank of Montreal (BMO).
Frank Clair Stadium (wikipedia entry lansdowne park)
Ottawa, Ontario (google maps)
Located in Canada's capital, Frank Clair stadium was originally built on its current site nearly 100 years ago. For the U20 world cup tournament, it will feature a FieldTurf playing surface, with seating available for 30,000 spectators. The stadium currently is without a primary tenant, after the Canadian Football League's Ottawa Renegades closed up shop in 2005. It has hosted several major events, including the CFL's Grey Cup on numerous occasions, most recently in 2004. Frank Clair Stadium will play host to 8 matches including matches in the round of sixteen and the quarterfinals.
Olympic Stadium (wikipedia entry rio)
Montreal, Quebec (google maps)
Built for the 1976 Olympics, the Olympic Stadium in Montreal has been seen as somewhat of an albatross. Ballooning costs left a legacy of debt which was only very recently repaid, and its primary tenant, the Montreal Expos, moved several years ago to become the Washington Nationals of Major League Baseball. Its unique architecture makes it a fixture of the Montreal skyline, but structural failures including a damaged roof have occurred in recent years. In its current configuration, it can seat approximately 56,000. For the tournament, a temporary grass surface will be brought in. Montreal will play host to 9 matches, through to the quarterfinals.
See here for a look at the stadiums in Victoria, Vancouver (Burnaby) and Edmonton.