Beijing (literally "northern capital" in Chinese) is the capital of the People's Republic of China and its second largest city in terms of population, after Shanghai. It is the political, educational, and cultural center of the People's Republic of China, while Shanghai and Hong Kong predominate in economic fields.Beijing has been settled since 1000 BC, but only became the capital of China under the Mongol rule in the 13th century. Beijing is a huge city (the emphasis being on "huge", with huge buildings, wide 12-lane streets and large open spaces in between (the Tiananmen square is 1 km wide). Beijing has a rough climate with cold winters, hot summers and short intermediate seasons in-between. The city also suffers from heavy pollution and poor air quality from industry and traffic.