Manhattan's Chinatown incorporates the highest concentration of Chinese people in the Western Hemisphere, with several signature Chinatowns developing across the city. Providing continuous 24/7 service, the New York City Subway is one of the most extensive metro systems worldwide, with 468 stations in operation. New York City is a center for media, culture, food, fashion, art, research, finance, and trade. It has one of the largest and most famous skylines on earth, dominated by the iconic Empire State Building. Weather in New York is heavily influenced by two continental air masses: a warm, humid one from the southwest and a cold, dry one from the northwest.