Fresnillo [frAsnE´yO] (2005 census pop. 110,892) is the largest city in Zacatecas state, north central Mexico. Fresnillo was founded in 1554 by Francisco de Ibarra. The city, a rail and highway junction, is the center of a rich mining area known especially for silver. Fresnillo is the location of one of the world's richest silver mines, the Mina Proaño or Fresnillo Mine, which belongs to the Peñoles mining company. It has a mining school, and agriculture (cereals, beans) and cattle raising are other important economic activities. Fresnillo is also the municipal seat of the municipality of the same name which surrounds it. The municipality had a population of 196,538 and an areal extent of 4,947 km² (1,910 sq mi).
Also an area wher the Cornish had astrong influence. See engine house made at Harveys Foundary.