Diamantina earned its name the hard way. In the early 1720s, prospectors in the hills of Minas Gerais found diamonds in the gravel of the streams, and for the next hundred years this high, rocky corner of Brazil supplied most of the world's stones. The Portuguese Crown clamped down at once, declaring a restricted diamond district, with a monopoly on trade, permits, soldiers and informers, and the town that grew up at the centre of it, on a cold plateau in the Serra do Espinhaço at around 1,200 metres, became rich and strange. Today it has about thirty-seven thousand people, and the colonial centre was inscribed by UNESCO in 1999.
The best-known resident was a woman, Chica da Silva, born into slavery, who became the companion of the wealthy contractor who held the diamond rights, and who ran a household with an authority that scandalised and fascinated her contemporaries. Her story has been told in books, films and a famous television series. More than a century later, the town produced another famous figure: Juscelino Kubitschek, born here in 1902, who became president of Brazil and built Brasília. His modest childhood house is a museum.
The old town is built of whitewashed walls, wooden balconies, carved doors and ochre-tiled roofs, laid out on steep, cobbled streets that climb in all directions. The cobbles are rough river stones, slippery in the rain and unkind to a bike, and several streets in the historic centre are narrow and steep enough that you will want to park and walk. The famous Vesperata, when musicians play from the balconies on certain evenings in the dry season, fills the streets with brass and crowds, and it is worth planning around if the date fits.
The roads that lead here follow the old Estrada Real, the Royal Road, along which gold and diamonds went to the coast and goods came back. They climb through bare, stony uplands of quartzite, grass and rock, with great skies and long views, and the curves are generous. Surfaces vary widely, from fresh asphalt to potholed stretches, and cattle sometimes drift onto the road. Fog can fill the plateau in the morning, and in the rainy months from November to March, afternoon storms are heavy.
Diamantina has fuel stations and all the services of a small city, and it is the best place to fill up before the long stretches south. Eat feijão tropeiro, a dish of beans, farofa, sausage and egg that was once the muleteers' food, and try the strong local cheese. The dry months, from May to September, are the best, though nights are cold at this altitude, so take a warm layer.