These complement each other, because the industrial area of Santa Laura is better conserved, while Humberstone has better preserved residential and service areas. The two saltpeter works are the most representative remaining vestiges of an industry that transformed the lives of a large proportion of the population of Chile, brought great wealth to the country. IntegrityThe attributes at the nucleus of the complex of the two saltpeter works still reflect the key manufacturing processes and social structures and ways of life of these company towns. As opposed to what occurred in many other saltpeter works, Santa Laura and Humberstone were not fully dismantled when they were no longer functional. AuthenticityThe two saltpeter works have remained better conserved that any other saltpeter works in the Pampa of northern Chile and what remains at the site is authentic and original.