Casa de la Moneda - Potosí (Bolivia)
This is the old Spanish mint where the silver from the mines of Potosí was transformed into coins.
The original minting machines are preserved in a near-perfect state. The oldest machines were made of huge wooden gears and powered by slaves or animals (depending on availability).
Later they used steam-powered machines, but luckily they kept the old machines untouched (just in case!).
This huge building is now a national museum.