No matter what the weather is, you'll want to bring a jacket to Muir Woods. The trees prevent almost all sunlight from reaching the forest floor, and Redwood Gulch (which Muir Woods is a part of) is situated so that when the fog rolls in, the cold, moist air runs straight through the park.
Photographers will find Muir Woods challenging to capture. Be patient, and, if you're serious, you should definitely bring a tripod.
Favorite thing: After visiting Sequoia National Park, I thought this place would be repetitive. And it was, a bit. But you can't help but be impressed by the redwoods. They are some of the oldest living trees on earth. And they grow in an area where rain is rare but moisture is not. The redwoods adapt to the west coast environment by absorbing moisture from fog and occasional rain. They are able to use this bit of water to sustain them and to grow to heights in excess of 300 feet tall. The sign in the picture gives some of the specifics on the coastal redwoods.
Drive up to the lookout (Vista Point) and get out of the car and walk down the path to the lookout.
Fondest memory: I came across this beach on the way to Stinson Beach years ago and fell in love with it. It is a small beach nestled in a cove of private homes. We were the only ones there at sunset.
Favorite thing: There is an easy loop trail through the park -- but don't miss the trails on the sides of the hills. The earlier you get to the park, the better your experience will be.
Favorite thing: The whole color range is green and brown -- with an occasional peek at the sky. Be sure to be still here. That's when the power of the trees will overwhelm you.