Topanga Canyon Docents. This small but active group of volunteers has created popular and fun educational programs of nature walks for families and school field trips. Their mission is to introduce people to Topanga State Park, the largest urban/wildland park in the world whose 25 square miles make up five percent of the land area of the City of Los Angeles. Learn about its uniquely adapted chaparral, live oak woodlands, coastal sage scrub, migrating birds on their way to Alaska and Mexico and the native Chumash and Tongva people. Karin Benson, Chair. TopangaCanyonDocents.org.