This article is about the town in Spain. For other meanings, see Almaden (disambiguation).
Almaden is a town on the northern slope of the Sierra Morena , in Spain, about sixty miles north of Cordoba. It is noted for its quicksilver mines, which are the oldest and among the largest in the world. The mines have been in continual production since Roman times.
The principal mine is directly under the town, and is about one-fifth of a mile below the surface.
The mines are worked day and night in the winter, but are closed during the summer, when the heat makes the fumes rising from the quicksilver too poisonous to breathe. Convict labor was long employed, but now hired men are used.