One thing to do in San Francisco is take a day or night tour of Alcatraz Island. It leaves from Pier 33 in Fisherman's Wharf (a tourist focused part of the city). Bring a jacket! It is windy on the Bay!
Full of local food, it is always fun to walk through the Ferry Building. You can also continue to walk throughout the Embarcadero and see beautiful sites of the Bay and the Bridge!
Angel island is a beautiful quick get away in the bay. You can take a ferry over and then rent bikes to ride up to the top of the island. There are great restaurants and views for miles!
For those that are a little more adventurous. The Palomarin Trail hike to Alemere Falls is one of our favorite hikes! You will hike to the top of a cliff with two small waterfalls that lead into a large waterfall. You can climb down the cliff onto the sand where to large waterfall is bringing fresh water to meet the ocean!