Oak Canyon Trail: Most Beautiful Beginner Hike in Mission Trails Regional Park! Mission Trails Regional Park in San Diego is one the largest urban parks in the United States, with over 8,000 acres of historical landmarks, rugged hills, vast valleys, and tall peaks to explore. Within this beautiful park, the Oak Canyon Trail is one of the most diverse hikes, showcasing interesting landmarks, giant oak trees, dramatic rocky gorges, and beautiful creeks and waterfalls. This trail is especially breathtaking during the spring with all the wildflowers. You can hike the Oak Canyon Trail as an out and back. However, we recommend doing this trail as a loop by combining Oak…