Bay seniors who think the south Peninsula is one large parking lot are mistaken. Alviso Park in Santa Clara County at the southernmost tip of San Francisco Bay (be wary of afternoon winds), comprises 19 bayside acres, a rich maze of sloughs and salt ponds for kayaking and lengthy paths and boardwalks for hiking. The avian life is remarkable here, over 250 species of resident and migratory birds. Dogs and bikes allowed in designated areas. One of the least visited, and therefore most peaceful, parks around. Free.