The Princeton Library has a new initiative for families and children to explore the great outdoors. Families can now check out a backpack loaded with information about parks and open spaces around Princeton. The backpack also includes a compass, binoculars, magnifying glass, New Jersey pocket field guides, nature log and more. The Marquand Park Foundation has included a guide with the location of some of its signature trees and a bookmark featuring the Little Free Library. The backpacks are available for check out at the Youth Services information desk.