Central Park Dog Park in Fremont, Calif., is the largest synthetic grass dog park in the nation, measuring 40,000 square feet. The new city park opened this past summer, offering dogs and their pet parents a place to exercise, play and socialize in a clean, mud-free environment. K9Grass by ForeverLawn was chosen as the surface for the park, due to features such as instantaneous drainage, simplification of waste removal and antimicrobial blades.