been one of the richest cities in China until the founding of the People's Republic of China with the introduction of new salt producing methods and advancing of technologies. It has had what is now the Zigong Salt Museum since 1736. The Fuxi River, a tributary to the Tuo River, snakes through the city's core. The area is very humid and the visibility can be reduced dramatically in the area due to ground fog. The humidity and fog of Zigong can be attributed to that it sits on what was once a vast inland sea. Changes in the environment caused the water levels to subside leaving salt, brine, and natural gas. Zigong is situated south of the Sichuan basin hill country. To the east of Zigong is Luzhou and to the west of Zigong is Leshan. To Zigong's south is Yibin and to the north-east is the city of Neijiang. Climate Attractions Zigong Dinosaur Museum In the 1980s, vast dinosaur fossils were excavated in the Shaximiao Formation, near the town of Dashanpu north-east from downtown Zigong, including a dinosaur named after the township, Dashanpusaurus. Because of the unique and intact bone remains, Zigong has ever since been attracting paleontologists and dinosaur enthusiasts from around the world. In 1987, the Zigong Dinosaur Museum () was established, becoming the first specialized dinosaur museum open in Asia. Mounted specimens include Omeisaurus, Gigantspinosaurus, Yangchuanosaurus hepingensis, Huayangosaurus and Xiaosaurus. Lantern Festival Zigong is the originator of the Chinese Lantern Festival - which has been copied in Beijing, Hong Kong, and Shanghai. As one of the Historical and Cultural Cities of China, Zigong is called "Lantern Town in the South Kingdom". In recent years, although the annual lantern show forces the local residents to endure unpredictable and extended blackouts during China's Spring Festival, the lantern festival is a boon for tourism in the remote but tranquil city and generates large revenues for the local government. The pattern of Lantern Show, a paradigm of China's festival economy, has been copied throughout China, which dilutes the uniqueness of Zigong's original version. As a measure to promote the city, the lantern show has already been brought to many cities in mainland China and even southeast Asia throughout of the years. Since China is on a Lunar calendar - known in the west as the Chinese calendar, Spring Festival - which is also known as Chinese New Year will vary