If you like a nice gradual climb, the fireroad is wide and in pretty good conditions, with very few ruts.
This is a long but gradual climb from the eastern side of the Marin Headlands. This fire road is in really great shape so makes it easy to meander along.
As you climb up and out of the woods, look east out to the two peaks of Mount Diablo. Below is Sausalito, the Belvedere Peninsula, and Tiburon. When you arrive at the top, you'll be able to connect with trails that view the Golden Gate Bridge
and the Rodeo Valley.
If you decide to head down on the Oakwood Meadow Trail
, there is a little pond where I have seen others let their dogs swim.