Having recently visited, and seeing as the previous reviews are quite old, I thought it might be time for an update. But actually, it seems like nothing has really changed in 10+ years in Diamantina. Maybe that is the charm. It is far enough from anywhere that it still doesn't see many foreign visitors compared to Ouro Preto and the other colonial Minas towns. Even in colonial times it was remote, being the starting point of the "gold trail" leading to Paraty on the coast. 

The horses aren't parked in front of the marketplace anymore but the well preserved centre still retains its easy-going colonial charm. Is it an essential visit to understanding the rich history of Minas Gerais? No. Go to Ouro Preto. If you are short on time it is skipable. If you have the time, the 5 hour journey from Belo Horizonte one way makes it best visited on an overnight trip which is plenty of time.