- Grand Plaza is conveniently located on the southwest corner of Las Posas Road and Highway 78 in the City of San Marcos, California. - The ±356,639 square foot mall is home to over 40 regional and neighborhood tenants including Nordstrom Rack, Bed, Bath & Beyond, Marshalls, Petco, and Sprouts Farmers Market. The center is strategically located in close proximity to CSU San Marcos and Palomar College with a combined enrollment of 39,000 students. - Seeking: Office, Medical and Fitness tenants for all second floor spaces. 101-197 S. Las Posas Road, San Marcos, CA 92069.