One of the longer hikes in San Pedro Valley County Park, the Hazelnut Trail is a challenging climb with nice views of the town of Pacifica and the Pacific Ocean. It is also a fairly solitary area for its location just a stone's throw from the suburbs of San Francisco. It is best hiked as a loop by connecting to the wide and popular Weiler Ranch Trail. Either direction is a fine way to take this hike, but going clockwise by doing the Weiler Ranch section first means the downhill views will be to the west over the Pacific, which is a good choice.
From the parking area, head up the Weiler Ranch Trail. You'll likely be sharing the trail with many walkers and runners, but past the Hazelnut Trail entrance at 0.75 miles, the crowd should disappear and no bikes or horses are allowed. For the next part of the hike, a long series of switchbacks cuts through the coastal brush lands. The views of the valley below and the surrounding hills are a great excuse to stop and catch a breath. Montara Mountain looms large to the south as the trail climbs about halfway to the top before hitting the high point and heading west for a much more gradual descent. This section has nice views most of the way down. There is a very nice grove of huge eucalyptus trees, which makes a fragrant change of pace on the descent.