Halden is a town and municipality in Østfold county, Norway, serving as an important border community at the southernmost crossing point between Norway and Sweden. Formerly known as Fredrikshald from 1665 to 1928, it is situated at the mouth of the Tista River where it meets the Iddefjord. The town lies approximately 120 kilometers south of Oslo, 190 kilometers north of Gothenburg in Sweden, and 12 kilometers west of the Svinesund border crossing. Halden is often referred to as Norway's "IT and Environment City" due to its focus on technology and sustainability initiatives. With a rich history tied to military fortifications and industrial development, Halden blends natural beauty, cultural heritage, and modern innovation, making it a key destination in the Oslofjord region. The municipality's coat of arms, featuring a knight on a mountain in yellow on blue, symbolizes the resilience of its inhabitants during historical conflicts.
Halden spans a total area of 642 square kilometers, with 596 square kilometers of land, ranking it 173rd in size among Norwegian municipalities. It has a population density of about 54 inhabitants per square kilometer. The town is positioned on the Iddefjord, a fjord that forms part of the border with Sweden, and is surrounded by forested hills, rivers, and lakes that contribute to its scenic landscape. Neighboring areas include Sarpsborg to the northwest, Rakkestad to the north, Aremark to the east, and Swedish municipalities such as Strömstad, Tanum, and Dals-Ed to the south and southeast. The terrain features a mix of coastal fjords, agricultural lands, and woodlands, ideal for outdoor activities like hiking and boating. Key geographical elements include the Tista River, which flows through the town, and nearby archaeological sites from the Nordic Bronze Age, including petroglyphs and tumuli.
Human settlements in the Halden area date back to the Nordic Bronze Age, with evidence found in the Svinesund region. The name "Halden" originates from the farm Hallen, first documented in 1629, derived from Old Norse words meaning "slope" or "hill." In 1665, it was renamed Fredrikshald in honor of King Frederick III of Denmark. The town played a pivotal role in Norwegian defense, withstanding six Swedish invasion attempts between 1658 and 1814 without being captured by force. Notably, during the 1716 siege by Charles XII of Sweden, residents burned their homes to prevent enemy occupation, an event referenced in Norway's national anthem. Charles XII was killed at Fredriksten Fortress in 1718, ending the Great Northern War. By 1835, Fredrikshald was Norway's seventh-largest town with 4,921 inhabitants and gained city status in 1838. The name reverted to Halden in 1928. On January 1, 1967, it merged with Tistedalen, Berg, and Idd to form the current municipality. During World War II, Nazi forces occupied the area, and post-war, Halden shifted toward industrial and technological development, including the establishment of research facilities.
As of 2025, Halden Municipality has an estimated population of 32,038, reflecting steady growth from 31,387 in 2020, with a 6% increase over the previous decade. This ranks it 18th in population among Norwegian municipalities. The population density stands at approximately 53.8 inhabitants per square kilometer. Residents are referred to as Haldensere or Haldensar, and the official language is Bokmål. The demographic composition includes a diverse immigrant population, with significant groups from Kosovo (566), Poland (483), Sweden (419), Somalia (342), Iraq (196), Denmark (145), Syria (135), Lithuania (133), Iran (107), and Germany (107), based on earlier ancestry data. The urban core of Halden town proper has around 22,000 residents, while the broader municipality encompasses rural and suburban areas.
Halden's economy emphasizes information technology and environmental sustainability, earning it the nickname "IT and Environment City." In the 1960s, it hosted Norway's most powerful mainframe computer at the Institute for Energy Technology (IFE), which continues to operate advanced labs like the Man-Technology-Organisation Lab (HAMMLAB) and a Virtual Reality Centre, attracting international researchers. The Halden Boiling Water Reactor, a research facility, closed in 2018 but persists in safety-related studies. In 2024, the municipality began exploring a Small Modular Reactor (SMR) project, identifying a potential site. Major employers include Nexans, which runs a large cable factory producing submarine power cables, umbilicals, and subsea pipeline systems. Historical industries like the Norske Skog Saugbrugs paper mill caused pollution in the mid-20th century, but cleanup efforts led to Halden being named Norway's Environment City in 1996. Tourism, tied to historical sites and outdoor activities, also contributes, alongside services and manufacturing.
Halden experiences a temperate continental climate with cold winters and warm summers, influenced by its inland fjord location. The annual average temperature is about 7.2°C (45°F), with total precipitation around 890 mm (35 inches) per year. Temperatures typically range from a low of 23°F in winter to a high of 68°F in summer, rarely dropping below 6°F or exceeding 77°F. Winters are overcast about 68% of the time, with average daily highs around 35°F. The meteorological station is at Buer.
Halden is rich in historical and natural attractions. Fredriksten Fortress, a star-shaped citadel built in the 17th century, houses museums and hosts events, offering panoramic views and insights into military history. Rød Herregård, one of Norway's best-preserved manor houses from the late 1600s to 1700s, features Baroque and English landscape gardens, period furniture, art collections, hunting trophies, and weapons; it was owned by prominent families like Tank and Anker and visited by royalty. Petroglyphs from the Nordic Bronze Age are scattered locally, with more along Oldtidsveien to Fredrikstad (20 km north) and in Tanum, Sweden (60 km south). The Halden Canal system provides scenic waterways for boating, while the Svinesund bridges connect Norway and Sweden dramatically. Høiåsmasten is a partially guyed TV tower, and Jellhaugen, a major tumulus west of town, is near the Gjellestad Ship site—a Viking Age longship discovered in 2018, excavated in 2020, and dated to at least AD 733. Halden Prison, opened in 2010, is a maximum-security facility renowned for its humane, rehabilitation-focused design, simulating village life with modern amenities like private cells, shared kitchens, and activity centers; it has influenced global prison reforms and won design awards, though criticized for being too lenient.
Halden's culture thrives on music, arts, and outdoor pursuits, with a history of producing notable artists and musicians. Outdoor concerts at Fredriksten Fortress and indoor ones at churches, pubs, and the student union are common. Musicians like Motorpsycho, Madrugada, Morten Harket, and Kurt Nilsen have recorded in the area. The intimate theatre hosts national and local plays, occasionally doubling as a concert hall. Festivals include a vegetarian food event in August and past editions of Tons of Rock (hard rock/metal, held in June until relocated to Oslo in 2019). Other events feature opera at the fortress (biennial in May/June), theatre performances, exhibitions, and community gatherings like Filipino-Norwegian cultural activities. Notable artists born here include painters Thomas Fearnley and Jacob Mathias Calmeyer, whose works are in the National Gallery in Oslo, and writers like Annette Abigael Hamilton and Sven Elvestad. Sports culture is active, with teams in volleyball (Halden VBK in Premier Division), ice hockey (Comet in Division 1), football (Kvik Halden FK in Second Division), handball, and curling. Popular activities include orienteering, hiking, canoeing, fishing, and gymnastics amid the forests and waters.
Halden is twinned with several international cities, though specifics vary. The town's border position fosters cross-cultural exchanges with Sweden, including joint events and trade. Recent developments include archaeological excavations at the Gjellestad Ship site and SMR investigations, highlighting its blend of heritage and forward-thinking initiatives. Challenges like past industrial pollution have been addressed through environmental policies, while the prison's philosophy underscores Norway's progressive justice system. Accessibility is excellent via road (E6 highway), rail, and proximity to Oslo, making Halden a gateway for exploring the Oslofjord region's history, nature, and culture.