Helsinki.

Borrowed from vernacular Swedish Helsinge, originally probably from a name Helsingå of the river Vantaa. The oldest record of the name is as Helsinga in 1351. Vanhankaupunginkoski, the rapids around which Helsinki was first founded, was called Helsingefors (literally “Helsinki rapids”) in older sources; this is also the origin of the current Swedish name Helsingfors (from the early 1550s, although it is not certain whether the rapids were first called this and the city was named after them, or vice versa). The Finnish form Helsinki is first attested in the late 18th century, but took until the 19th century to become established. Practically every researcher that has sought to explain Helsinge has connected it with Swedish hälsing (compare Hälsingland, Helsingborg ~ Hälsingborg, Danish Helsingør), but the exact reason for this connection has long been a source of debate. Options include: Details * Swedish hälsing is derived from hals (literally “neck”) (with i-umlaut), which has been thought to refer to nearby narrow bodies of water (e.g. in the case of Hälsingland, referring to Kvarken). Based on this, it has been proposed that the name, in case of Helsinki, refers to the nearby rapids in the Vantaa river. However, the exact geographical motive for this name remains in question, as rapids are generally not referred to as 'narrow' parts of water in place names (such designations are instead usually used of straits). Indeed, note that the village of Forsby (modern Koskela in Helsinki) is named after its location by the rapids (fors (“rapid(s)”) + by (“village”)). However, it has been proposed that prior to glacial rebound, the modern river valley of the Vantaa river could potentially have been a narrow strait, or that the name refers to the Gulf of Finland. ** Note that the semantics of the Swedish etymology have also been called into question; hals could equally well refer to a narrow part of land (i.e. a peninsula), for which there are no grounds in Helsinki's case (the idea that this name would refer to the Vironniemi peninsula onto which Helsinki was relocated in 1640 is anachronistic, as the name is clearly significantly older). * Another possibility is that the name derives from an anthroponym (personal name). Such a name could have referred to someone from Hälsingland, but was not necessarily a geographical designator. If the name was originally a personal name, it was likely first given to a farm, in which case the river was named after it. According to Kepsu (2005), the name may have referred to even a single settler family from Hälsingland, and then used as a village name *Helsingby or *Hälsingby. It however doesn't seem that there is direct evidence for such an origin, e.g. no records of such a farm name. * It has also been proposed that Helsinge was directly named after Hälsingland, according to the theory that the Swedish-speaking settlers of the village of that name originated from there. However, historians have later concluded that this is unlikely to have been the case, and that the majority of settlers instead came from Uppland. That makes this rather unlikely, but does not necessarily rule out the aforementioned idea of an anthroponymic origin. * Another theory now considered unlikely ties the name to the meaning “barnacle goose” also found in hälsing. Such meanings are also found in locally spoken varieties of Swedish, and are found in some names for seaside places, but is highly unlikely to be a semantic match for what was likely originally a river or farm name.