Which Colombian mine contains an underground cathedral carved from salt?

The Colombian mine containing an underground cathedral carved from salt is the Salt Cathedral of Zipaquirá.

Located near Zipaquirá in Colombia’s Cundinamarca Department, the church occupies tunnels in a halite mountain roughly 200 metres underground. The site developed from miners’ devotional practices: workers had carved a small sanctuary in the mine around 1932 so they could pray for protection before beginning work.

A larger first cathedral opened in 1954, but structural and safety concerns led to its closure in 1992. A new cathedral was then built in a separate section of the mine and inaugurated on December 16, 1995. Its spaces include Stations of the Cross chapels, a dome, and three interconnected naves, with architectural details and religious imagery carved into the salt rock.

Despite its popular name, it is not a cathedral in the formal Catholic sense because it has no bishop or cathedral seat. It is nevertheless a functioning church, pilgrimage destination, and major tourist attraction. Nemocón is a nearby salt-mining site, but it is not the Colombian mine identified by this question.