Next to the San Cayetano church in Valenciana is the San Ramón bocamina or pithead, where, it is said, that, in 1548, the Guanajuato mother lode was struck.
The San Ramón mine was subsequently sold off to the heirs of the Count of Valenciana and the Otero family, who rebuilt the facilities, adding towering walls and extending the tunnels further down. From 1825, it came under the ownership of the Anglo-Mexican Company Limited and, since that time, it has had many further owners.
Although no longer a functioning mine, the facilities have been kept in good condition and, today, visitors will find a pleasant spot with a restaurant and a helpful tourist information service.
What is now the bar was once the explosives store. On the second floor there is a small museum displaying objects relating to the mining industry that brought such fame and riches to viceregal Guanajuato.