[3] Kalundborg is mainly a trading and industrial town, but is also well known for its five-spired Church of Our Lady, which is closely associated with King Valdemar I and the Archbishop Absalon.

Kalundborg is at latitude 55°41′N, longitude 11°6′E, about 110 km (68 mi) west of Copenhagen on the island of Zealand (Sjaelland).

The history of Kalundborg Industrial Symbiosis activities began in 1961 when a project was developed and implemented to use surface water from Lake Tisso for a new oil refinery, to save the limited supplies of ground water.

The material exchanges in the Kalundborg region include: conservation of natural and financial resources; reduction in production, material, energy, insurance and treatment costs and liabilities; improved operating efficiency; quality control; improved health of the local population and public image; and realisation of potential income through the sale of by-products and waste materials.

Kalundborg Municipality is home to approximately 19,000 jobs of which 13,000 are in the private sector (December 2014).

[11] The Northwest Line (1874) connects Kalundborg with Holbæk and Roskilde and the rest of the Danish rail network.