Iowa Code § 300.1: Public recreation.

Boards of directors of school districts may establish and maintain for children and adults public recreation places and playgrounds, and necessary accommodations for the recreation places and playgrounds, in the public school buildings and grounds of the district. The board may cooperate under chapter 28E with a public agency having the custody and management of public parks or public buildings and grounds, and with a private agency having custody and management of buildings or grounds open to the public, located within the school district, and may provide for the supervision and instruction necessary to carry on public educational and recreational activities in the parks, buildings, and grounds located within the district.