The first indoor waterpark was built in Edmonton, Alberta, Canada in 1985, and the first U.S. waterpark was built in Wisconsin Dells, Wisconsin in 1994. With temperature controlled interiors, they are year-round destinations, regardless of the season.
To help you find the right indoor waterpark, we have pulled together five different lists:
Wikipedia - Top 30 Largest Indoor Waterparks
Budget Travel - Top 10 Indoor Water Parks in the U.S.
About.com - The Top 10 Indoor Water Park Hotels
America's Best & Top Ten - Best Indoor Water Parks
Top Eight - Top Eight Indoor Waterparks