The Watiki Indoor waterpark is located in Rapid City, SD just off Interstate 90 where you would exit to go to Mt. Rushmore.  The park is a 30,000 square foot indoor waterpark, which is the largest of it's kind in the four State area.   Attached to the waterpark are two very new hotels.  They are the Fairfield Inn & Suites and the La Quinta Inn & Suites.  With children, it is a great location to base out of so that you can easily access the sights in the Rapid City/Black Hills area while providing an entertaining and relaxing place to stay.