At the eastern edge of the Silicon Valley, the Sunnyvale Baylands is a sprawling refuge that varies from the neatly manicured lawns and creative landscaping of Sunnyvale Baylands Park to a former landfill's manmade hills and the treatment ponds of the Sunnyvale Water Pollution Control Plant.
Amid all these constructed features you'll find some of the Bay Area's best bird-watching. The water treatment ponds and levees are crowded with huge flocks of waterbirds in fall and winter. Egrets and herons hunt along the sloughs and channels and wade in the marshes. Flotillas of white pelicans cruise the ponds for food. In the uplands you'll find burrowing owls, songbirds, and raptors.
There are miles of uncrowded trails through the low hills and on the levees around the ponds and sloughs. The main Bay Trail route runs about 6.4 miles from Alviso to Stevens Creek, but it provides access to many more miles of side trails and several recreation areas. A good way to explore the area is to start at Sunnyvale Baylands Park on Caribbean Drive north of Highway 237. Take the Bay Trail east from the park, turn left before the Calabazas Creek Bridge, then head west to the entrance by the water treatment plant, a total of 2.5 miles. Climb the hills for panoramic views of the Bay and Silicon Valley. You can continue on the Bay Trail west for 3.5 miles past Moffett Field to the shoreline or take a nearly five-mile loop around the water treatment ponds.