Mariana is 12 km east of Ouro Preto and the two are easily combined. Minibuses (lotações) run the route regularly throughout the day, taking about 20 minutes. From Belo Horizonte, buses run directly to Mariana and to Ouro Preto; the journey takes about 2 hours. There is no direct train service from major cities.
If you are driving, the road from Ouro Preto to Mariana passes through beautiful mining country and is straightforward. Parking in Mariana's historic centre is possible but the streets are narrow.