This is Brake (Unterweser). I can confirm the identification by Moos as I am living in Brake: The picture must habe been painted before around 1960, since the site has changed since. The bridge does no longer exist.
After research in the net and with the help of people who live there, the place is located:
It is definitively Brake (Unterweser) Germany. I have found the page of a historic postcard: external link the buildingsd can easily be identified.
Sorry, the link doesn't work. Try this:external link
According to the "Museumshafen Övelgönne e. V." this location is not a part of the Hamburg Hafen but another international port of the North Sea.
Last week I contacted the responsibles of the society "Museumshafen Övelgönne e. V.". According to them this is not the Museumshafen with the Schiffsanleger Neumühlen. They confirmed that this is a harbour with tidal waters.
The steamer in the background is probably a oversea freight liner of the HAPAG LLoyd line. Nevertheless the location could be another part of the Hamburg harbour or onother international port of the North Sea like Bremen, Bremerhaven, Cuxhaven, Emden or even in the Netherlands.
Teilzeithamburger is correct. Now it´s called: Övelgönner Museumshafen / Schiffsanleger Neumühlen.
look like one of the smal baltic sea habours around 1900. but i dont know where exactly
Danzig, gdansk in Poland