Kalundborg is famous as the location of a large broadcasting facility, the Kalundborg transmitter. The city is also home to the largest coal-fired power station in Denmark.
Kalundborg is a mainly trading and industrial town, but is also well known for the beautiful five-spired Church of Our Lady, which is closely associated with King Valdemar I and the famous Archbishop Absalon. The church itself is said to have been built by Absalon's brother, Esbern Snare.
Kalundborg is also the traditional seat of the aristocratic Lerche family. Their stately home, Lerchenborg, the best example of rococo architecture in Denmark, can be seen in the town's outskirts.
Kalundborg is the birthplace of the Norwegian Nobel laureate author Sigrid Undset, who lived there during the first two years of her life, before her parents emigrated to Norway in 1884.
Ferries connect Kalundborg westward to the island of Samsø.
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 Kalundborg area was first settled in 1170 at a natural harbour at the head of the narrow bay today known as Kalundborg Fjord. It became more urbanized during the nineteenth century and had grown into a major industrial centre by the mid-twentieth century.
Kalundborg Municipality has approximately 20,000 inhabitants, and its network is the most published example of Industrial Symbiosis. 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 City of Kalundborg took the responsibility for building the pipeline while the refinery financed it. Starting from this initial collaboration, a number of other collaborative projects were subsequently introduced and the number of partners gradually increased.
By the end of the 1980s, the partners realised that they had effectively "self-organised" into what is probably the best-known example of Industrial Symbiosis. 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). Novo Nordisk has extensive production facilities in Kalundborg with a total of more than 2,400 employees. Since 1999 they have invested more than DKK 7.5 billions in the complex. Pronova BioPharma Danmark, a bulk manufacturer of Omega-3 products which was acquired by BASE in 2014, also has a manufaction plant in Kalundborg.
The port plays a centroal role in the town's economy. It is a municipal self-governing port with independent finances. Kalundborg Container Terminal is served by Unifeeder on a weekly basis. Schultz Shipping is a local shipping company. As of 2015, the port is being expanded with a new west harbor on the south side of the Asnæs peninsula.
Statoil Refining Denmark operates Denmark's largest oil refinery on the harbor with a capacity of 6.6 million ton oil products per year. Haldor Topsøe is one of the companies that has facilities at Kalundborg Tank Terminal.