1 Real - Carlos III

Carlos III's monetary reforms of the 1760s pushed the Spanish colonial mints toward milled coinage, but Potosí's transition was notoriously uneven. The 1 Real cobs from this mint had long carried a reputation for irregular weight and fineness — a scandal that had triggered royal investigations as far back as 1649, when mint officials were found systematically debasing the silver. By the late 1760s, the macuquina production that overlapped with early milled output made this a transitional window at one of the highest-altitude mints in the world, operating above 4,000 meters in the Bolivian altiplano.