From the North
Take why 101 southbound
Exit at 2ndSausalito exit (just before the GG bridge)
Bear right onto Alexander ave; proceed back under the freeway
Follow Alexander ave .2 miles; turn left onto bunker road
From the South
Take 101 across the GG bridge
Exit Alexander ave; bear right
Follow Alexander ave .2 miles turn left onto Bunker road
Once you have passed through the tunnel, you will pass a number of historic buildings, Bunker road turns into Mitchell road along the Rodeo lagoon. There is plenty of parking there.
Retrace your route to along Bunker road, there is a path on the right side of the road, go right up the hill on Field road towards the visitors center, take FortBarry road to the end. From here it is .5 miles to the lighthouse. The views from here are panoramic of the Golden Gate bridge, Marin Headlands and the ocean. You will pass through a short tunnel, to the foot bridge that was re-opened 04/14/2012 to the public. This is the 2nd oldest lighthouse on the West coast, the first being on Alcatraz, Pt Bonita lighthouse was originally located higher on the hill, due to low lying fog, the lighthouse was relocated to its current place.
When going back you can make a loop by turning Left into the main parking lot, at the far side you will see a trailhead that will take you down to the beach where you can relax, cross the foot bridge back to your car.
This is a family and pet friendly area, a moderate hike that is steep in a few places. It is well maintained by the US park service and Coast Guard
No special shoes are required however it is always very windy, it can get cold quickly so bring layers, there are a number of picnic tables and view benches throughout the area. There are a number of optional hikes originating from this area, the Marin Headlands Visitor center has a all the maps and friendly advice.
Bring a camera and binoculars