|Poppies and Yarrow in Bloom at Windy Hill|
That's just an excuse of course.
Sure, the 7 mile loop from Portola Valley up to the top and back down is a great way to get in some hill climbing, but with wildflower season in full force here on the Peninsula, you're not hearing any complaints from local hikers, taking in the flores and colores. The vistas are fantastic as well. All along the way you're treated to sudden peaks at the top of the rounded hills, and excellent views of the San Franciso Bay below.
Less mobile folks can drive along Skyline Boulevard, and gain easy access to picnic tables at the top turn-around point. From there you can get some lovely vistas of the Pacific Ocean on one side of the road, and the Bay from the edge of the picnic area. You can also amble along a shortish side trail to the top of one of the rounded domes - perfect for flying a kite.
And yes, you can take the pooch. Dogs are allowed on several Windy Hill trails. (If you start off in Portola Valley, check the dog signs carefully as there are multiple trail heads, some of which do not allow dogs).
BTW, Windy Hill is within athletic bike riding distance of Stanford University and Silicon Valley, though it's not a mountain bike area.
On my Flower-Lovin' Hiker's Bookshelf