San Francisco is surrounded by natural wonders and destinations of scientific interest for visitors of all ages. Across the Golden Gate Bridge are the Marin Headlands — coastal bluffs, rugged hiking trails, vast wetlands, protected valleys, historic landmarks. At the Bay Model Visitors Center (2100 Bridgeway, Sausalito; 415-332-3871), the Army Corps of Engineers operates a working scale model of the Bay. The Marine Mammal Center (Bunker Rd. at Rodeo Lagoon; 415-289-7325) cares for injured, sick or orphaned seals and sea lions stranded along the coast. Marin Headlands Visitors Center (415-331-1540) is a favorite resting place for brown pelicans, blue herons and egrets. And Point Reyes National Seashore (25 miles northwest of S.F.; 415-663-1092), a Northern California treasure, boasts 30 miles of coastline, 140 miles of trails, majestic vistas, herds of tule elk, acres of wildflowers. A haven for rare birds, it is a paradise for birdwatchers.

The 3,849-foot Mt. Diablo State Park (925-837-2525) beckons hikers with 100 miles of trails and a museum at the summit. Lindsay Wildlife Museum (1931 First Ave., Walnut Creek; 925-935-1978) focuses on living harmoniously with nature. U.C. Berkeley's Lawrence Hall of Science (Centennial Drive near Grizzly Peak Blvd., Berkeley; 510-642-5132) is a public science museum and a center for teacher education, research and curriculum development. Oakland Museum of California (1000 Oak St., Oakland; 510-238-2200) has the state's most detailed exhibition of California natural history. The largest refractor in the Western U.S. regularly open to the public is at Chabot Observatory (4917 Mountain Blvd., Oakland; 510-530-3480).

On Hwy. 1, Fitzgerald Marine Reserve and Pillar Point tide pool offer a beautiful beach that is safe and interesting for children. Be sure to check nespapers for low tide times. Año Nuevo State Reserve (Hwy. 1, 13 miles south of Pescadero; 650-879-0227) is home to a large herd of elephant seals. At the Children's Discovery Museum (180 Woz Way, San Jose; 408-298-5437), 150 exhibits and programs help youth understand our complex world. Tech Museum of Innovation (201 S. Market St., San Jose; 408-279-7150) provides interactive exhibits highlighting advanced technology.

Harbor seal pups at Marine Mammal Center in Marin County