Combining beach, lagoon, crest, and canyon, this looping hike touches upon every natural landscape the community of greater Del Mar (the west-of-Interstate-5 part, anyway) has to offer. On a typical early-summer day, with a tepid temperature and a good breeze, the journey of six miles is a one-water-bottle effort. Hike or run as you see fit, and be aware that early Sunday morning is great if you like solitude.
Start off at Durango Drive and Del Mar Heights Road, four blocks west of Interstate 5, where plenty of curbside parking is available on Durango or any other nearby quiet street. Head 0.3 mile north on Durango to where it curves right and becomes Lozana Road. Take the steep, eroded path on the left descending into Crest Canyon Open Space Park. In barely a hundred yards, at the shallow bottom of Crest Canyon, pick up a wide path heading north and gradually downhill. Note the elaborate drainage systems along the sandy canyon bottom, which have solved erosion problems of the past. A number of large Torrey pines grace the slopes of Crest Canyon; long needles in bundles of five give their identity away. You'll see plenty more of these pines near the end of the hike.
At the 1.0-mile mark of the hike, you reach Racetrack View Drive, across from the southern arm of San Dieguito Lagoon, a tidal basin currently undergoing an elaborate restoration. Make a left, and soon you'll be on San Dieguito Drive, a sparsely traveled roadway edging along the scenic lagoon. Be cautious -- the road is narrow and you must share space with cars.
When you reach Jimmy Durante Boulevard (1.75 miles into the hike), turn left, follow it and then Camino Del Mar ahead to 15th Street in Del Mar's business district. Hang a right and descend to the adjacent Seagrove and Powerhouse parks (2.7 miles), where you cross the railroad tracks and get access to the beach. Now go south along the coastline. All but high tides are fine (and low tides are perfect) for the 1.8-mile straight stretch of sand-walking ahead.
At 4.5 miles into the hike, turn inland under the Camino del Mar bridge and find yourself in a large parking lot for Torrey Pines State Beach (restrooms and water are here). Walk out to the parking lot entrance on Carmel Valley Road, cross over to the other side, and keep going on Del Mar Scenic Parkway. In a short while, this residential street ends at the boundary of the Torrey Pines State Reserve Extension. Like the main Torrey Pines reserve just south, this serene, sage-scented patch of landscape harbors scattered but robust specimens of the rare Torrey pine, which can be seen either on the main trail ahead -- the Mar Scenic Trail -- or along side trails both left and right. If you stick to the Mar Scenic Trail, you reach the south end of Mar Scenic Drive at 5.6 miles, and Del Mar Heights Road at 5.9 miles. Your starting point on Durango Drive is just one block east.