The Macul winery was entrusted by Luis Cousiño to a French architect firm in 1870. Located in the center of the estate, it was built using bricks and limestone bonded with lime and pebble; a mixture of sand and egg white. The cellar was built seven meters deep with double walls where air flow circulates to create a passive ventilation system. This ensures a constant temperature of 14 ° C and humidity close to 75% for optimal wine aging in barrels. This marvel of the nineteenth century is considered one of the most efficient and grand cellars of the world.