I'm not a native speaker of English, so I might be wrong, but could I say working "at" the port aswell? Working "in" a port feels a little bit weird to me...
I must have missed the comments but I actually added "at" to this sentence over a year ago, so it's also accepted.
In addition to what Lundgren8 writes, arbetar på can also mean "work on" as referring to the current task being worked.
It depends on the place, some places are constructed with på and some with i.
Yep. And a few other cities, like Nynäshamn, Karlshamn and Hargshamn for example. There are also a few places in the Anglophone world named Newhaven, which is etymologically exactly the same name as a few Swedish places called Nyhamn. :D
I'm now guessing that the German city of "Hamburg" might be etymologically related with swedish word "hamn". Am I right?
Distantly related perhaps. The precise origin of "ham" in Hamburg is uncertain, I believe.
Swedish "hamn" / English "harbor", "port" = From Old Norse hǫfn, from Proto-Germanic *habnō. (https://en.wiktionary.org/wiki/hamn#Etymology_2)
Proto-Germanic "*habnō"... harbor, haven (https://en.wiktionary.org/wiki/Reconstruction:Proto-Germanic/habnō)
German "Hamburg" = In A.D. 825, construction started on the Hammaburg, or Hamma Castle, on ground between the Elbe and Alster rivers. It is from this structure that the city takes its name.
The origin of "ham" in Hamburg seems uncertain but English "harbor"/Swedish "hamn" do not appear to be directly related (https://en.wikipedia.org/wiki/History_of_Hamburg#Etymology).
Boddason points out below, the German Wiki suggests three possibilities as well for "hamma" in Hammaburg but my German is not good enough to translate it into English. (https://de.wikipedia.org/wiki/Hammaburg)
There seems to be a less common Swedish-English translation of "hamn" as "haven" which is intriguing in the context of "Hamburg" but I can't find links here and it doesn't appear in the Hamburg word origin discussions that I've seen.