Unlike Foothills Park, you do not need to be a Palo Alto resident (or accompanied by one) to enjoy Arastradero Preserve's rolling hills.
Getting There:
From Hwy 280, take the Page Mill Road exit and head West on Page Mill Road, away from Downtown Palo Alto (if you're taking 101, exit on Oregon Expressway). Then turn right on Arastradero Road. There will be a small sign indicating the dirt parking lot on the eastern side of the street. Note that parking is not allowed on the street.
The Hike:
There are many trails in the preserve, including the loop right behind the open-air visitor center and bathrooms. However, I will be describing a 4.5 mile loop across the road.
Continue past the visitor center/ bathrooms (last chance for flushing toilets and potable water at the water fountains) to a marked road crossing (please use the road crossing -- people drive WAY too fast on the road, its dangerous to cross the street at a different location since there is no shoulder). Cross the street and continue straight on the Juan Bautista de Anza trail for ~0.3 miles. Then take a right up the hill onto the Meadowlark Trail (unsigned). Continue left on the Meadowlark Trail for 0.5 miles. For even better views, I recommend staying right and climbing the unsigned "Bonus Hill Trail". You'll end up a little to the right of where the Meadowlark Trail would have brought you, so take a left after you descend the hill, and quickly turn right to stay on the Meadowlark Trail for another 0.3 miles. Then turn left onto the Acorn Trail and enjoy the shady oak trees for 0.25 miles. Turn right on the Arastradero Creek Trail and continue straight until you see signs for the Woodrat trail on your right. Take the Woodrat trail and switchback up for about 0.5 miles. Head left towards the Bowl Loop, then turn right at the Meadowlark Trail. Watch for trail markers indicating the vista point spur trail on your left and climb up for views of the Bay Area, with Mount Diablo looming across the bay. After resting at the top, meander down and turn left back onto the Meadowlark Trail. At the junction with the Acorn Trail, keep straight to stay on Meadowlark, then turn right to join the Juan Bautista de Anza trail, passing the Arastradero Lake (no swimming or boating, but fishing allowed with a CA license), and heading back to the parking area the way you came.
Notes: