The Adventure Playground at the Berkeley Marina was opened 30 years ago in 1979. It is a wonderfully unique outdoor facility where staff encourage children to play and build creatively. Come climb on the many unusual kid designed and built forts, boats, and towers. Ride the zip line or hammer, saw, and paint. By providing these low risk activities Adventure Playground creates opportunities for children to learn cooperation, meet physical challenges and gain self confidence. - Pictures of a fort building project. The concept for Adventure Playgrounds originated in Europe after World War II, where a playground designer studied children playing in the "normal" asphalt and cement playgrounds. He found that they preferred playing in dirt and lumber from the post war rubble. He realized that children had the most fun designing and building their own equipment and manipulating their environment. The formula for Adventure Playgrounds includes Earth, fire, water, and lots of creative materials.