Ouro Preto (formerly Vila Rica — "Rich Town") made its fortune from gold, and then renamed itself after the black gold ore that defined it. The colonial-era wealth is still written across the town in baroque churches, grand mansions, and cobblestone streets that climb steep hillsides to offer views of the surrounding mountains.
It is one of the best-preserved colonial towns in Brazil — a UNESCO World Heritage Site — and no trip to Minas Gerais is complete without it. The baroque churches are particularly remarkable: the Basílica de Nossa Senhora do Pilar has an interior heavily decorated in gold leaf, and the Igreja de São Francisco de Assis contains masterworks by Aleijadinho, Brazil's most celebrated baroque sculptor. Beyond the churches, the Museu da Inconfidência on Praça Tiradentes tells the story of the 1789 plot for Brazilian independence, and the Mina do Chico Rei lets you walk into one of the colonial-era gold mines.
Ouro Preto is about 100 km southeast of Belo Horizonte and is reachable by bus in roughly two hours. It can be visited as a day trip, but an overnight stay allows you to wander the streets in the evening when the day-trippers have gone.