You can take a side trip down into the Tennessee Valley and hang out at the little pond. It is a little work hiking down, but can be fun.
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.