Minas is on Ruta 8, about 120 km northeast of Montevideo. Buses from Montevideo are frequent enough for a simple overnight or weekend trip, and regional services connect onward toward Villa Serrana and smaller Lavalleja towns.
A car is useful if your plan includes Cerro Arequita, Parque Salus, Salto del Penitente, or Villa Serrana. Distances are short, but rural bus times can limit what you can combine in one day.