answers: Abraj Al Bait
context: Europe. The tallest building in China as of 2015 is the Shanghai Tower by the U.S. architectural and design firm of Gensler. It is 632-meters (2,073 ft) tall, with 127 floors, making it in 2016 the second-tallest building in the world. It also features the fastest elevators, which reach a speed of 20.5 meters (40 feet) per second or 74 kilometers an hour. Most skyscrapers are designed to express modernity; the most notable exception is the Abraj Al Bait, a complex of seven skyscraper hotels build by the government of Saudi Arabia to house pilgrims coming the holy shrine of </s> existing palace buildings. One example is the palace of Knossos on Greek island Crete. This palace, which started construction in 2000 BC, reached its biggest size in 1500 BC with a size of 20,000 square meters (215,278.208 square feet) and 1,300 rooms. The Roman emperor Hadrian's Villa at Tivoli, Italy was a complex of over 30 buildings build between 118 and the 130s AD, covering an area of at least 250 acres (1 mio square meters, or 10,763,910 square feet) of which much is still unexcavated. The villa was the greatest Roman example of an Alexandrian garden, recreating a sacred </s> or reinforced concrete frameworks and curtain walls of glass or polished stone. They use mechanical equipment such as water pumps and elevators. From the 1930s onwards, skyscrapers began to appear around the world—such as in Latin America (such as São Paulo, Rio de Janeiro, Buenos Aires, Santiago, Lima, Caracas, Bogotá, Panama City, Mexico City, Monterrey) and in Asia (Tokyo, Shanghai, Hong Kong, Manila, Jakarta, Singapore, Mumbai, Seoul, Kuala Lumpur, Taipei, Bangkok). Immediately after World War II, the Soviet Union planned eight massive skyscrapers, seven of which were built by 1953, dubbed the "Seven Sisters of Moscow". The Building of Moscow
question: what is the most expensive building in the world