List some import aspects about location Ljubija in given text
1. Because of its iron ore resources, Ljubija became one of the most significant destinations for the region's economy in the 19th century.
2. Ljubija grew to be one of the world's largest iron mines after World War II, employing more than 5,000 people at any given moment.
3. Prior to being amalgamated with Prijedor, it was governed as an independent municipality until 1963.