The city of Ouro Preto (black gold) was founded when gold, colored black, was found in this area around 1698. The discovery of gold provoked a gold rush, and within 50 years attracted over 110,000 people, at the time making it the biggest city in Brazil. In the 18th century some 500,000 kilos of gold was extracted from the mines, situated in the surroundings of the city, with slaves carrying out the heavy work.
Many, with gold ornamented churches, were build in Ouro Preto during the city's golden era, while wealthy locals constructed beautiful houses in colonial baroque art.
At the end of the 18th century the gold boom was over, the mines yielded no further treasure and many people left the city. Due to its limited economic importance in the last decade, no modern office buildings have sprung up in its center, unlike in many other Brazilian cities. Ouro Preto is a national monument since 1933 and since 1981 it is under protection of the UNESCO, representing the supreme masterpiece of colonial architecture in Brazil.

A walk through the steep and narrow streets of Ouro Preto is like walking back in time. Little has changed over the centuries, the city center has been practically untouched by modern times, with many beautiful examples of Brazilian religious architecture. Of course it is possible to visit an old gold mine.