Guadelupe Oak Grove Park, San Jose
Beautiful Park full of sandy paths and oak trees with some grassy landscapes too. It is especially amazing in the morning. Beware - there are bobcats and tarantulas in the park (I have seen one of each).
Pfeiffer Park, San Jose
Totally unknown little park next to Los Alamitos Trail that offer some wonderful grassy fields as well as paths. It changes over the year from green in winter/spring to yellow summer/fall.
Ed Levin Park, Milpitas
Especially beautiful when the long yellow grass is there (just by the parking).
Meadow on Saratoga Ave., Saratoga
When you get off Fwy 85 NB on Saratoga Avenue towards San Jose, there is a small meadow just a minute away on the left (you can't miss it, it is the only meadow surrounded by houses).
It changes throughout the year, now it has yellow mustard flowers, later on it has beautiful rye grass and orange poppies.
Montalvo Villa, Saratoga
It is very elegant park that is popular among newly weds. One needs to get there first thing in the morning to avoid crowds.
Ulistac Natural Area, Santa Clara
Wild park that offers a variety of paths, meadows and fallen branches. It is the only place in Bay Area that I encountered mosquitos - fortunately they are active at dawn only.
Cuesta Park, Mountain View
Very convenient location that offers variety of backgrounds. From green park with benches and paved paths to wild grassy fields and yellow paths. Also - very colorful in the fall. Watch out for prickly grass and wasps nests in the ground (there is one close to the single big tree in the wild part).
Holbrook-Palmer Park, Atherton
This park offers beautiful paths, green grass meadow and some architectural features - barn door, steps, walls.