Beijing (known as Peking in English until the late 20th century,) is the capital of China and one of the most populous cities in the world. Beijing is the second largest Chinese city by urban population and is the nation's political, cultural and educational center. Beijing is home to a great number of colleges and universities, including several well-regarded universities of international stature, such as Peking University and Tsinghua University. As the last of the Four Great Ancient Capitals of China, Beijing has been the political center of the country for much of the past eight centuries. The city is renowned for its opulent palaces, temples, parks, gardens, tombs, walls and gates, and its art treasures and universities have made it a center of culture and art in China. Beijing has seven UNESO World Heritage Sites – the Forbidden City, Temple of Heaven, Summer Palace, Ming Tombs, Zhoukoudian, Great Wall, and the Grand Canal. Beijing hosted the 2008 Summer Olympics and was chosen to host the 2022 Winter Olympics, which will make it the first and only city to ever host both events. Beijing or Peking opera is a traditional form of Chinese theater well known throughout the nation. Commonly lauded as one of the highest achievements of Chinese culture, Beijing opera is performed through a combination of song, spoken dialogue, and codified action sequences involving gestures, movement, fighting and acrobatics. Beijing cuisine is the local style of cooking including Peking Roast Duck and Fuling Jiabing. Teahouses are common in Beijing. The cloisonné (or Jingtailan, literally "Blue of Jingtai") metalworking technique and tradition is a Beijing art specialty, and is one of the most revered traditional crafts in China.