The Coastal Trail at the Marin Headlands in the Golden Gate Recreation Area in Mill Valley, California is an easy 0.4 mile one-way trail that leads from Conzelman Road over to the Golden Gate Bridge lookout area.
The entire Coastal Trail is made up of multiple trails in this area including the SCA Trail, Slacker Trail, Julian Trail, and more; however, this is the only trailhead labeled 'Coastal Trail' within the park.
Hiking within the initial downhill section, across the street from the end of the SCA Trail, you'll get a great view of the Golden Gate Bridge along with a large field of various types of wildflowers. When you reach CA-101, you'll find a staircase that leads beneath the bridge and over to the Golden Gate lookout point.
Parking: Alternatively, you can park at the Golden Gate lookout point and hike over and up the hill to the SCA Trail to continue along the scenic Coastal Trail.