This mine is a giant gash carved diagonally through the core of a mountain following the trail of a silver vein deeper and deeper underground. To see this gash and think that all the stone and ore that once occupied this space was mined and extracted by hand provokes a sense of wonder. The mine opened in 1586, using forced Indian labor. Accidents, tuberculosis, and silicosis caused the workers' early deaths. The mine was extremely rich, yielding gold, copper, zinc, iron, and lead in addition to silver, but it eventually closed when an attempt to use explosives resulted in an inundation of water in the lower levels. English-speaking guides are available only sporadically, although the tour is eye-opening even for those who don't speak Spanish. A visit also includes a short, unremarkable train ride.
The mine's back entrance is a block from the cable-car terminal. I prefer this entrance because most people start at the main entrance, so you can avoid the crowds. When you get to the ticket office, buy your ticket right then. According to the rules, a tour must begin within 15 minutes after the first ticket is purchased. Often, I've had the guide all to myself (a tip is appreciated). After the tour is over, you can exit by the front entrance, which puts you on Juárez, a few blocks above Hidalgo.
For directions on getting to the front entrance, see La Mina Club.