Engelsbergs oljefabrik, Industrial heritage museum on Barrön island, Västmanland County, Sweden

Engelsbergs oljefabrik is a preserved oil refinery on the island of Barrön, also called Oljeön, in Lake Åmänningen near Ängelsberg, Västmanland. Built in 1875, its wooden buildings include refining halls, oil cellars, and worker housing, showing how crude oil was processed into kerosene, weapons grease, and machine lubricants.

Pehr August Ålund built a refinery north of the works by Lake Snyten in the late 1860s, but it burned down after a lightning strike. For safety he moved the operation in 1875 to the island of Barrön in Lake Åmänningen. Crude oil came mainly from the USA, tallow and fat from Russia, and tar from Galicia, carried by barge up the Strömsholm Canal. Refining stopped in 1902 and lubricant production ended in 1927 after protective tariffs were abolished.

The factory demonstrates how workers and their families lived on the island, with homes built near the production buildings. The layout shows how closely work and home life were connected during that industrial period.

The island is reached by the passenger ferry Petrolia from the mainland during the summer season. The site is part of the Ekomuseum Bergslagen network, and the nearby Engelsbergs bruk, a UNESCO World Heritage site, can be combined with a visit. Wear sturdy shoes for the paths between the preserved buildings.

The island is nicknamed Oljeön, Oil Island, and the ferry that carries visitors across Lake Åmänningen is called Petrolia. The refinery belongs to Preem and forms part of Ekomuseum Bergslagen, while the neighbouring Engelsberg ironworks is a UNESCO World Heritage Site.