Sarpsborg is a town and municipality in Viken county, formerly
Østfold, Norway. It has almost 57,000 inhabitants and is one of
Norway's ten largest cities. Sarpsborg is part of the region Nedre
Glomma, where Fredrikstad / Sarpsborg has grown together into
Norway's sixth largest town. The municipality borders in the north
towards Våler and Skiptvet, in the east towards Rakkestad and
Halden, in the west towards Fredrikstad and Råde and in the south
The river Glomma and Sarpsfossen, Europe's largest waterfall, have been crucial to the city's growth. In 2016, Sarpsborg turned 1000 years old, and the town's name is composed of the name of the waterfall and Borg, which was the name the founder King Olav the Holy used in 1016. The king sailed up the Glomma, but had to stop when he came to the waterfall. Borg was Norway's capital from the founding of Nidaros (Trondheim) took over in 1030. Later, the waterfall became the basis for Borregaard's and Hafslund's sawmills and factories, and the city became known as an industrial city. East of Sarpsborg center, Borregaard's factories wind their way along 4 km of the riverbank.
Sarpsborg is located south of the former Østfold county. The city center itself is built on the ridge Østfoldraet, and is therefore slightly higher than the surroundings. The municipality's highest point is Gastgiveren in Trøsken, 216 meters above sea level. The bedrock consists mainly of gneiss. Sarpsborg consists of 184 km² of productive forest, 79 km² of cultivated land and unproductive land, 27 km² of built-up areas and 25 km² of fresh water, respectively. Around 8 km² of the municipality is protected through the seven nature reserves Skjebergkilen (4 km²), Skinnerflo (2 km²), Vestvannet (1 km²), Jørstadmyra (0.3 km²), Hansemakerkilen (0.2 km²), Ågårdselva (0.1 km²) and Solgårdhavna (0.03 km²) as well as the landscape conservation area Valbrekke (0.1 km²).
The municipality has 80 km of coastline towards the Oslo Fjord, divided into miles Tosekilen into the town Skjærvika, the half mile long Skjebergkilen into Høysand and E6 and 3 km long Grimsøykilen and Røsneskilen, both less than half a mile from Sweden. The river Glomma flows along the east side of Tunøya, on which Sarpsborg center is located. The glomma is dammed up by the ravine and pressed over a rock cover where it forms Sarpsfossen, Europe's largest waterfall after water flow. Just west of Sarpsfossen is a landslide pit after the large clay landslide in 1702. Just over a kilometer below the waterfall, the river is no straighter than that you can drive ships from the Oslo Fjord and up to Sarpsborg harbor. The west side of Tunøya is surrounded by Mingevannet, Vestvannet, Ågårdselva and Visterflo, which together form a 20 km long tributary to Glomma. Raet also dams up the lakes Tunevannet (2 km²), Isesjø (6 km²) and Tvetervann (1 km²) which are located in a row in the northern part of Sarpsborg's buildings. Despite the fact that Tunevannet and Isesjø are attacked by algae, Fredrikstad sarpinger refuses to swim in Tvetervann, which Fredrikstad has controlled since 1906. Sarpsborg also has many smaller ponds. Those that are larger than a football field in area are five ponds west of Glomma in Trøsken (Tjernetjern, Isebakketjern, Sætretjern, Søndre Svarttjern and Skogtjernet), two in Sarpsborgmarka (Landemyra and Ørretdammen) and fourteen in Skjebergmarka (Børtevann, Oppsjidt, Lsjjet, Lsjjet , Svarttjern, Grøvletjern, Galtetjern, Krysstjern, Grinderødtjerna, Morttjerna, Syverstadvannet and Tulletjern).
Especially for Sarpsborg's fauna is the tuna fly, which is fought with municipal funds because it occurs in large hordes every summer. Tuneflua is a knob that is named after Tune in Sarpsborg. The tuna fly hatches in the lower parts of the Glomma watercourse, especially in the area around Sølvstufoss. The daisy has been chosen as Sarpsborg's municipal flower.
Sarpsborg has a temperate climate, where the average temperature is lowest in February (-4 ° C) and highest in July (16 ° C). The temperature usually passes 20 degrees during the day from June to August, while there is usually night frost from December to March. For several years in the 2000s, Sarpsborg has been the city with the most sunny days, and VG calculated that Sarpsborg would have Norway's best summer weather in 2008, based on a combination of cloud cover, temperature and rainfall.