The solutions to these problems are many: bringing back recess (cut by many schools in favor of more class time), reducing homework, and creating safer pedestrian and bike routes to schools and playgrounds. But spaces in which to play, and a constantly renewable source of things to play with, are essential to improving early childhood outcomes. The toy librarians of the 1930s had it right: Toys should be free. And the library is the perfect platform, because citizens already understand it as a public good and distribution hub.

The oldest continuously operating toy library is the Los Angeles County Toy Loan Program, administered by the Department of Public Social Services and founded in 1935. A dime-store operator noticed that kids were stealing toys and decided, rather than reporting the youth to the police, he would fill his garage with surplus toys and lend them out. The program now serves 35,000 children a year, distributing playthings at 54 locations including parks, child-care centers, YMCAs, and one book library.

“Generally we have found the program is a success in lower-income areas, but there is a new surge of interest among parents who like the idea of recycling,” says Marcia Blachman-Benitez, director of the DPSS Toy Loan Program. Much of the program’s stock of toys comes through donations, both from individuals and from local toy and game companies, including Mattel and Universal Studios. Participants in good standing are given a new toy of their own to keep every five weeks, which can include donated craft kits that are one-use-only.

Read: How libraries are becoming modern makerspaces

Different locations select different items from the stock: Some like electronic learning toys, while others focus on the wood trucks that the San Fernando Valley Woodworkers make for the program. “Culturally, some locations don’t like Barbie with a bikini,” Blachman-Benitez says. “We had a location in Koreatown that asked that clothing for the dolls be modest.” Oh, and no guns except Nerf.

The toy library builds upon the social foundation that people already understand from traditional book-lending libraries. As the media scholar Shannon Mattern has argued, libraries aren’t just physical buildings, but a kind of infrastructure for sharing and disseminating knowledge. That means that toy libraries benefit more than just children. They’re not meant to be used as child-care centers (most toy libraries ask that a caregiver be present), and that can help parents as much as children: Adults can learn about the developmental phases of play in context.

The Pittsburgh Toy Lending Library’s 1974 founding documents address that opportunity directly: “Babies and young children from all socio-economic backgrounds need attention and play. Specifically, they need positive interaction and intellectual stimulation from adults if they are to develop to the fullest potential.” But how are adults to know how to provide that interaction? And where are they to find other parents and caregivers going through the same experience? “Early parenthood is such a confusing, identity-altering, and in many ways disenfranchising moment,” Emily Kane, PTLL’s former president, told me. Toys help adults and children communicate.