In recent years, Pachuca, the capital of Hidalgo state, has burst out of the ring of hills that once hemmed it in, its expansion fuelled by the need to move industry away from Mexico City. By Mexican standards, though, it remains a fairly small city, its centre easily walkable and full of colonial mansions built on the profits of the rich silver-mining country all about. If you have the time, it is worth venturing to nearby towns where the mining heritage is more apparent and the clean mountain air is refreshing.