The derrick
Over the wellhead.
Nekitarc — CC BY-SA 4.0 · David Stanley from Nanaimo, Canada — CC BY 2.0 · Phreakster 1998 — CC BY 2.5 · Zhangzhugang — CC BY-SA 3.0 · Zhangzhugang — CC BY-SA 3.0 · Zhangzhugang — CC BY-SA 3.0 · Zhangzhugang — CC BY-SA 3.0 · Zhangzhugang — CC BY-SA 3.0
The world's first well to go deeper than a thousand metres, drilled in Zigong, China's «salt capital», and finished in 1835 at a depth of 1,001.42 metres to bring up natural gas and the black brine that is boiled down into salt; it has been a protected national monument since 1988. It was sunk by the percussion method invented under the Song dynasty, in which a heavy bit is raised and dropped again and again to chip through the rock little by little, and it worked for more than 150 years; its works have since been restored, brine is no longer drawn, but gas still flows. Visitors see the tall timber derrick over the wellhead, the house of the great wheel that hauled buckets up from the depths, and the stove house, where huge iron pans boiled the brine over gas flames. Tickets cost CNY 25, and it is open from 8.30 am to 5.30 pm, or until 5 pm in winter, per visitor guides.
Over the wellhead.
Great salt pans.
That hauled the buckets.
Changyantang, Da'an District, Zigong, Sichuan
Because it drew salt from deep brine wells for many centuries and was one of China's main salt-producing centres; the Shenhai Well is the most famous of its wells.