At Las Gallinas, hundreds of acres of grasslands and wetlands (ponds, marshes) surround a small water treatment facility. The marshes recede in all directions for hundreds of yards, and are surrounded by the beautiful hills of Marin. Acre for acre, it has some of the greatest diversity of birdlife I’ve ever seen, a favorite resort of many kinds of ducks, herons, egrets, shorebirds, raptors and songbirds. Numbers are very impressive. Walking tour is about 1-2 miles around ponds. Total species observed usually range from 40 to 50.