Marston Canyon is one of Balboa Park’s canyons with beautiful trails that are very lush and green in the springtime. If you have a mountain bike this area will be a ton of fun. These trails will connect you to Balboa’s BMX trails & the Bridle Trail which are also great. It is quiet and peaceful and there are inclines so you will get a little exercise at the very least.
The Upas St. footbridge takes you over highway 163, heading into downtown. This bridge was built in 1946 and connects Balboa Park to Hillcrest. Do not enter this area at night as it is quite isolated and said to not be safe.
On the southwest side of the park is a gateway into four trails:
The 1.0 mile trail follows sidewalks to take tree-lined route loops through the south side of Balboa Park’s West Mesa. Difficulty level: Easy. Follow the #41 round blue trail markers.
The 1.6 mile trail follows sidewalks, stairways, unpaved trails and some road surfaces. Experience unique perspectives of the West Mesa canyons. Difficulty level: Medium. Follow the #42 square orange trail markers.
The 2.6 mile “Jerry Schad Memorial Trail” follows sidewalks and some road surfaces. It is a tree-lined, gently sloping route through the entire West Mesa, featuring some of the park’s finest botanical treasures. Difficulty level: Medium. Follow the #43 square purple trail markers.
The 3.3 mile trail follows sidewalks and some road surfaces. Explore the 1915 Panama California Exposition section of the park by way of the West Mesa and Cabrillo bridge. Difficulty level: Medium. Follow the #44 diamond red trail markers.
Although there are other entrances too:
You will walk across the Upas St. footbridge: