Muir woods is located 12 miles north of San Francisco; about a 45 minute drive. Parking at Muir Woods is extremely limited. Expect parking to fill very early in the day. There is a Muir Woods Shuttle offered weekends, from April to October.
The fees are $10 per person, or free for one group (one car) with the National Park Annual Pass
Muir woods is actually a valley, with the Redwood Creek flowing through the park.There is a nice short hike along Redwood creek. Actually it’s more of a walk that an hike, but the views of the redwoods are wonderful.
The park itself has only 6 miles of trail, but many trails extend from Mount Tamalpais State park, if you are looking for a longer day hike.