Canyon Sin Nombre is a 5 mile lightly trafficked out and back trail located near Julian, CA and is rated as moderate. The trail is primarily used for hiking and mountain biking and is accessible from November until April.
A nice hike through a narrow canyon with many geological features. There were many people there when we hiked it! The "trail" is a jeep road which gets quite a bit of traffic. A nice walk from the road or drive a mile to the canyon opening. Went in the fall, spring would be best due to lack of greenery.