Tijuana Estuary is a coastal wetland located in southern California, near the U.S.-Mexico border. It serves as an important habitat for various species of birds, fish, and other wildlife. The estuary is part of the larger Tijuana River National Estuarine Research Reserve, which aims to protect and restore the natural environment. The estuary is characterized by its diverse ecosystems, including salt marshes, mudflats, and riparian zones. It provides recreational opportunities such as hiking and birdwatching, making it a popular destination for nature enthusiasts. The area also plays a crucial role in water quality improvement and flood control.