Nasunogahara is a sprawling park with dozens of things for families to enjoy. Each year in the summer, for six weeks only, they open their outdoor pools. There are four pools in total. One for toddlers, one for small children, a general pool and one with waves. There is a large water slider too. Facilities include coin lockers, a shop and a restaurant. Of course there are changing rooms and toilets too.
The pools are open from the middle of July to the end of August annually. During the season, the pools are open from 9 am to 5 pm daily, with last entry at 4 pm.