Walk: Fort Cronkite Loop, Cavallo Point
Distance: 6 miles
Cavallo Point is a truly lovely resort and spa in an unparalleled setting. It is just across the Golden Gate from San Francisco (10 minutes) and a thoroughly tranquil and pleasant place to stroll around - on the large, expansive green, onto adjacent trails or along the water. They also offer a calender of cooking, artistic and other activities. Totally first class and well done re-invigoration of old military buildings - very accessible even if you don't spend money on dining or spa services.
Every time I go there - which I did today for a casual but sumptuous Thanksgiving meal after a long hike - I am so impressed and reminded I should do it more often and keep it in mind to recommend to (outdoorsy) people looking for a 'perfect' place to stay in the Bay Area.