The Arroyo Seco goes all the way from the JPL/Devils Gate Dam area in the north, and joins the LA River in the south near Elysian Park. The trails basically follow the wash. It is a favorite for out and back relatively flat endurance training by time or making 3 mile loops around the Rose Bowl and Brookside Golf Course in Pasadena. There are two favorite starting spots: The end of Altadena Dr. in Altadena and the Brookside Park Aquatic Center near the bathrooms on the north side. For more maps, directions and info, click on Arroyo Seco Trail Guide.