The main tourist office is located in a kiosk on Plaza 6 de Agosto. No maps are available here, but the staff is knowledgeable and helpful. I recommend making a quick stop at the Museo Sacro Jerusalén, on Avenida Camacho at the corner of Avenida del Maestro. The church here dates from 1708. To really understand the history of Potosí, you have to visit Casa Nacional de la Moneda, Calle Ayacucho between Quijarro and Bustillos (tel. 0102/6223-986), once the biggest building in the Americas. This former Spanish royal mint it is now dedicated to Bolivian weapons, modern art, minerals, and archaeology. Convento Museo Santa Teresa, Calle Santa Teresa 15 and Calle Ayacucho (tel. 0102/6223-847), was a working convent from 1691 through 1976 (nowadays, the sisters live next door). Here, the nuns were separated from their callers by a dark screened wall. They weren't allowed to touch or see their guests; they could only exchange words. You can visit the impressive church and countless galleries full of colonial art, antiques, Murano glass, and hand-painted porcelain dishes.
Visiting the Mines -- The history of Potosí is inextricably linked to Cerro Rico. Taking a tour of the mines will open your eyes to a different side of Potosí, to the world of the people who actually work here. Let me warn you beforehand that it's not a pretty picture. Not much has changed here over the past few hundred years. Fortunately, the miners now work in cooperatives, and they do earn a percentage of what they find. The average salary here is equivalent to about $100 (£50) a month.
You will see workers igniting dynamite to open new areas, shoveling rocks, and carrying heavy loads, all in one of the most abysmal work environments that you could ever imagine. These miners often spend 24-hr. stretches in utter darkness, with cigarettes, soda, and coca leaves as their only form of sustenance. There are no proper stairways with handrails and the paths are narrow and very steep; and there is mud everywhere, which makes walking treacherous. Expect to get dirty. I would recommend that anyone with heart or breathing problems or claustrophobia skip the trip to the mines.
There are several companies in Potosí that offer mine tours. The best ones use guides who are former miners. Overall, however, the quality of the tours is horrendous: The equipment (hard hats, waterproof clothing, gloves, boots, lamps, surgical masks) is often in poor condition, and the guides can be unreliable. Koala Tours, Ayacucho 5 in front of Casa de la Moneda (tel. 0102/6222-092), is one of the more reputable companies. Tours leave Monday through Saturday, but it's best to go on a weekday because the mines are quiet on the weekends. The 5-hr. tour costs Bs80 ($10/£5) per person; a percentage of the profits is donated to the cooperatives working in the mines.