Between Solana Beach and Encinitas, this is the most complex of the estuary systems in San Diego North County. A 7-mi network of trails surrounds the 1,000-acre park, where more than 700 species of plants, fish, and birds (many of them migratory) live. Be sure to stop by the LEED-certified gold New San Elijo Lagoon Nature Centre. The center, open 9 to 5 daily, offers museum-quality exhibits about the region and a viewing deck overlooking the estuary. Docents offer free
public walks every Saturday from 10 to 11:30 am.