La Mesa, CA

ZIP code 91943 is located in San Ysidro, California. This area is well-known for its proximity to the U.S.-Mexico border and the San Ysidro Port of Entry, the busiest land border crossing in the world. Other landmarks in the area include Las Americas Premium Outlets, offering a variety of shopping and dining options, and the Tijuana River Estuary, a protected wetland and bird-watching area.