Humberstone and Santa Laura Saltpeter Works

Humberstone and Santa Laura are in Chile, in South America.

They stand in a desert where it almost never rains.

The two saltpeter works stand in the Pampa, a desert in northern Chile, about 45 kilometers from the port of Iquique. UNESCO calls it one of the driest deserts on Earth.

The Pampa lies between 1,000 and 1,200 meters above sea level, between the high Andes Mountains to the east and the Coastal Range to the west. Days can reach around 30°C, and nights can fall to 2°C or below.

The works lie in the Tamarugal Pampa, about 45 km from the port of Iquique, on a desert plateau at 1,000 to 1,200 m between the Andes and the Coastal Range. ICOMOS describes virtually no annual rainfall and temperatures from around 30°C by day to 2°C or below at night.

Water filtering down from the Andes through the porous Pampa formed small lakes near the coastal ridge; as it evaporated, it left saltpans and saltpeter beds in cracks in the rock. The World Heritage property covers 573.48 ha, and its two main sites stand about 1 km apart.

Humberstone had houses, a school, a theater and even a swimming pool.

It was a whole town in the desert!

Humberstone keeps its town. The streets were laid out in a regular grid, with a main square in the middle. Around the square stand a market with a clock tower, a theater, a general store and a swimming pool made of iron sheets.

The houses were simple one-story buildings of Douglas fir wood with metal roofs. The museum says Humberstone had more than 3,000 people in its busiest years.

Humberstone's 'Camp' was laid out on a regular grid crossed by a diagonal railway, with communal buildings around a main square. Most of these were built between 1934 and 1936: a concrete market with a clock tower, an Art Deco theater of rendered timber, a general store with a bakery, and a swimming pool of bolted iron sheets with a diving board. A school and a hospital also survive.

Houses were single-story Douglas fir buildings with stuccoed walls and sheet-metal roofs. UNESCO also names costrón and 'Pampa concrete' as distinctive local building materials, used with calamine and timber brought from other latitudes.

This photo shows a tall chimney and old rusty sheds in the brown desert.

The sky is clear and blue.

This photo shows old factory buildings at Humberstone: a tall chimney with a metal frame around it, long sheds with rusty roofs and piles of old timber, with the flat desert stretching away to the horizon.

The works became a National Monument in 1970, and the Saltpeter Museum Corporation, set up in 1997, now looks after them. Each year, people from all over the Pampa meet at Humberstone for Saltpeter Week.

The photograph (rewbs.soal, uploaded to Flickr in 2007; its Commons description calls it old factory buildings in Humberstone) looks over the chimney, sheds and workyard to the open Pampa.

After the works closed, buildings and machinery were sold and partly dismantled; the sites were declared a National Monument in 1970. UNESCO kept them on its List of World Heritage in Danger from 2005 to 2019 to help find resources for conservation. The camanchaca, a dense, salty mist from the Pacific Ocean, can seriously damage metal, timber and even stone, and UNESCO says conservation must take it into account. Former workers and their families still gather here for Saltpeter Week.