Upper Newport Bay is a large coastal wetland estuary on the southern edge of Costa Mesa, separated from the developed Newport Harbor by a narrow channel. It is a significant nature reserve and one of the best birdwatching spots in Southern California. The surrounding bluffs and marshes attract migrating shorebirds, ducks, and raptors throughout the year.
Kayaking through the bay is an excellent way to see it — rental outfitters operate near the Back Bay Science Center on Irvine Avenue. The Peter and Mary Muth Interpretive Center provides an overview of the ecology. Trails along the top of the bluffs offer views across the water and out to the Pacific.