Shenhai Well is a major natural and cultural relic under state protection, and it is one of top scenery sights in Zigong City. The well is located beside the mountain of Ruanjiaba in Da’an District of Zigong with an area of 2,000 m2. The well location is 341.4 m above the sea level, lies beside barrier pool named Changyantang. The well was started to drill from the 15th of Dao Guang of Qing Dynasty (the year of 1835), and was finished after 3 years. The well is 1,001.42 m deep, which can produce not only halogen but also gas. At the time, the spraying quantity of water containing halogen was about 14 m3 for everyday, and produced 4,800 ~ 8,000 m3 of natural gas providing fuel to burn 14 tons of salt. As it is recorded in some relating materials, after Shenhai Well had been finished for 11 years, a Russian named Shemilrov succeeded to drill a shallow well in 1846 and collected a little amount of oil from the well. In addition, after another 13 years, an American named Derick in August of 1859 bored a well at a depth 21.69 m and only collected 1.8 tons oil from the well.