A little oases I enjoy that allows me to unwind and still feel like I'm not missing out on the wonders of the Bay Area is the Berkeley Marina and Cesar Chavez Park. The marina itself provides 1100 berths--a great place to do some boat watching--as well as a public pier that doesn't require a fishing license.
Cesar Chavez Park, which sits adjacent to the marina, provides large stretches of open grass and hilly terrain, wildlife and bird watching opportunities, and views of San Francisco, the Bay Bridge, and the Golden Gate Bridge. On a clear day, one can see the Bay Bridge, San Francisco, and the Golden Gate at the same time from the parking turnabout (see photo below).
The Bay Trail is nearby so the park is accessible by bike as well as vehicle, and parking is free and plentiful. The Dorothy Stegmann Trail, which is 1.25 miles long, runs around the diameter of the park and is paved. The paved path is mostly flat and is wheelchair friendly. And, happily, the park is dog friendly; there's even off-leash--though unfenced!--dog areas.
My favorite part of visiting the park is doing a little bird and wildlife watching. There are so many birds, in fact, that birdsong is a throbbing, palpable force depending on the time of day. One side of the park belongs to the red-winged blackbird, and these daring individuals often zip over the path right in front of walkers and joggers and forage in the long grass at the path's edge. Another part of the park belongs to the burrowing owl, though I haven't seen one yet. It's also quite magical to watch the Forster Tern hunting for a meal; this bird hovers above the water like a helicopter before diving for its prey. One can also watch ground squirrels sunning themselves on rocks or munching on seed heads in the long grass. On the water, one can see grebes, a variety of ducks, pelicans, and more going about their birdy business.
The whole park has a wild feel I have found few other places in the Bay Area. It always feels like I'm deep in nature while wandering the park and yet I'm not too far from Berkeley and the freeway, and the park provides such comforts as bathrooms (or rather, port-a-potties), benches ideally placed for the views, and water fountains.
For those who don't mind spending money on a trip to the marina, there are three restaurants nearby including the Sea Breeze Market & Deli. There is also a Doubletree Hotel on site for Bay Area visitors, and Golden Gate Fields is just down the road for the horse racing enthusiast. In the summer the marina offers classes at its Shorebird Park Nature Center on water activities and marine biology for children up to 16 years old (more here: http://www.ci.berkeley.ca.us/summer_programs/). Participants can learn about canoeing, sailing, dragon boats, and local wildlife.
So whether you're a visitor to the Bay Area and need a break from the tourist activities or you're a resident and need a break from the tourists, Berkeley Marina and Cesar Chavez Park are definitely Bay-Area-miss-me-nots.
Yep, that's the Golden Gate out there.
Notice the shipping cranes in the distance.
Behold, the red-winged blackbird.
On the horizon from left to right, the Bay Bridge (new span in front, old behind), San Francisco, and the Golden Gate Bridge.