The El Castillo complex is comprised of the El Castillo Mine and the San Agustin mine, which is located approximately 10km from the El Castillo mine and 100km north of Durango city, Mexico. El Castillo is a conventional open pit operation utilising drill, blast, load and haul mining methods. Ore is crushed and heap leached, with the resulting pregnant leach solution processed in a carbon-in-column (CIC) circuit. The loaded carbon is then trucked to Agonaut's La Colorada Mine for processing further. The El Castillo mine has two leach pads, the East and the West, whereas the San Agustin Mine which commenced operations in September 2017 adopts a multiple-lift, single-use leach pad.