fog. In the spring, the temperature varies greatly between day and night, with a little rain and some winds. Summertime is often hot, humid and rainy. Autumn days have falling temperatures with little rain and are cool and clear with abundant sunshine. Architecture Pingyao still retains its urban layout from the Ming and Qing dynasties, conforming to a typical ba gua pattern. More than 300 sites in or near the city have ancient ruins. The city has over a hundred streets and lanes, lined with close to 4,000 17th–19th century shops and residences. The streets and storefronts still largely retain their historical appearance. The city walls of Pingyao were constructed in 1370, the 3rd year of the Hongwu Emperor of the Ming. They enclose an area of about . The town is accessed by six barbican gates, one each on the north and south walls and two each on the east and west walls. This pattern is similar to that of a turtle (the head, tail and four legs), earning Pingyao the moniker "Turtle City." The walls measure about high, with a perimeter of . A 4m wide and deep moat can be found just outside the walls. Aside from the four structured towers at the four corners, there are also 72 watchtowers and more than 3,000 battlements. The number of defensive works supposedly represents the number of Confucius's disciples and other students. The walls are considered among the best-preserved ancient city walls on this scale. Demographics As of 2009, Pingyao had a population of 48,531 people living in 16,634 households. 12,132 residents held local hukous and 36,399 were from other parts of China. Governments Pingyao Ancient City and its environs are organized as the town of "Gutao", the seat of Pingyao County. Gutao directly oversees 10 administrative villages: Economy As of 2009, the town had a labour pool of 19,059 people. 3,811 farmers worked 9977mu () of arable land, producing 33.7m RMB of crops, livestock, and other goods. The local focus is on increased mechanization and working the available land intensively. The area is well known for its beef and also produces grain and cotton. The rest of the workforce is divided between industry and the service sector, particularly tourism. Industry produced 840mRMB and was focused on improving the energy efficiency of its practices. A local specialty is lacquerware. The service sector, including tourism, produced less income than industry—790mRMB–but