Located adjacent to the city of Los Angeles, the second largest urban area in the United States, the Santa Monica Mountains represent one of the largest protected areas of the Mediterranean-type ecosystem. The Santa Monica Mountains National Recreation Area is part of the Mediterranean Coast Network that protects some of the most significant examples of terrestrial Mediterranean-type ecosystems and coastal marine environments anywhere in the world. The climate of the Mediterranean ecosystem along with the diverse topography in the Santa Monica Mountains has created a landscape filled with unique natural resources. Over 1,000 plant species provide habitat for approximately 500 mammal, bird, reptile, and amphibian species. Leashed pets are allowed on the park's trails and in developed areas, such as picnic areas, parking lots, and along gravel and paved roads. Pets are not allowed in the buildings or in the backcountry. Leashes must be no longer than six feet.