Nyköping

Including Arnö, the locality on the southern shore of the bay just a couple of kilometres from the city centre, Nyköping would have above 36,000 inhabitants. Commonly, Arnö is referred to as a part of the city proper. It forms a wider conurbation with the neighbouring minor municipality and town of Oxelösund 10 kilometres (6.2 mi) south of its outskirts. The municipality is much larger, although sparsely populated outside of the urban area.

Nyköping directly translates to "New Chipping" in English. The prefix ny is translated as "new" and köping is an archaic Swedish word and cognate to the English chipping, commonly used as a suffix for cities in the south central region of the country. Nyköping is the name that appears on coins in 1230 and in historical records from the 13th century. Aros is the name of the town found in the archaeological records from before 1230, indicating a new era and a new name sometime around 1230. The city is located near the open Baltic Sea on the Stadsfjärden inlet, and is regarded as a coastal location. Rivers Nyköpingsån and Kilaån reach the Baltic Sea through the southern end of downtown.