It's either the Calgary Stampede or the Rocky Mountains.
The first tourist attraction in Springfield that is popular is the Discovery center. The second most popular tourist attraction is the Springfield Nature Center. The third most popular tour attraction is the Fantastic Caverns. These are the three most popular as rated by the users of Yahoo.
Fitz - 2007 is rated/received certificates of: Canada:14A Canada:14A (Alberta)
Losing Will - 2007 is rated/received certificates of: Canada:14A (Alberta)
Dreamers - 2006 is rated/received certificates of: Canada:13+ (Alberta)
Dasavatharam - 2008 is rated/received certificates of: Australia:MA (2008) Canada:14A (Alberta/Ontario) Canada:13+ (Quebec)
I Heart Regina - 2010 is rated/received certificates of: Canada:14A (Alberta)
The Phoenix Agenda - 2006 is rated/received certificates of: Canada:14A (Alberta)
Eating Buccaneers - 2008 is rated/received certificates of: Canada:14A (Alberta/Ontario)
Cas and Dylan - 2013 is rated/received certificates of: Canada:14A (Alberta/Ontario)
The Wild Hunt - 2009 is rated/received certificates of: Australia:MA15+ (2012) Canada:14A (Alberta/Ontario) Canada:13+ (Quebec)
The Shortest Dream - 2005 is rated/received certificates of: Canada:13+ (Alberta/British Columbia)
Margarita - 2012 is rated/received certificates of: Canada:14A (Alberta/British Columbia/Manitoba/Ontario)