Los Angeles, officially the City of Los Angeles and often known by its initials L.A., is the most populous city in California, the second most populous city in the United States, after New York City, and the third most populous city in North America. With an estimated population of four million, Los Angeles is the cultural, financial, and commercial center of Southern California. The city is known for its Mediterranean climate, ethnic diversity, Hollywood and the entertainment industry, and its sprawling metropolis. Los Angeles is the largest city on the West Coast of North America.