Note: Most of these photos were taken in springtime. This area does not look like this all year long. You will be sorely disappointed in the summer if you visit it and expect it to be bursting with flowers and greenery.
Personal Experience: The Bridle Trail really comes as a surprise if you happen to stumble upon it. Basically being located in the heart of the city, it's not the type of place you'd expect to come across in this area. This trail is located west of Route 163, and in fact, during parts of the trail you will walk right alongside the freeway and underneath the Cabrillo bridge! You can access the trail from several points including along Balboa dr. & 6th ave and a spot several yards north of the lawn bowling site.
I love this trail for so many reasons: the tranquility, unique beauty to San Diego, the flower fields in the springtime, fresh air. It all evokes clarity and peace of mind. I would not recommend going alone as you will occasionally come across a suspicious person or two. Balboa is notorious for lewd activities, such as sexual assaults and drugs.
I believe those are red cedar trees growing, but not positive. Can anyone confirm?
Update as of May 2016: I have noticed the trees are dying. Turns out that a bark beetle is destroying all of the pines in California from the inside out. How devastating!
Anza Borrego Desert
Cuyamaca State Park