The island of Kaltehofe is bounded to the north and east by Billwerder Bay, which continues to the south in the Alte Dove Elbe (formerly connected to and part of the Dove Elbe). 125 meters to the north is the island of Billwerder Ausschlag, connected to the Billwerder Bay barrier (bridge connection). In the south-west it is separated from the Elbe island of Peute, which is part of Hamburg-Veddel, by the 230 meter wide North Elbe. The island is 1.8 km long from north-west to south-east and 520 meters wide in the central area, tapering at the ends. The area is around 60 hectares.
In the south, the Kaltehofe is connected to the mainland (Elbwasserfilterwerk in Moorfleet, Billwerder Insel) via the 400 meter long and 110 meter wide main Elbe dyke. On the island is the Elbe water filtration plant built by the Hamburg Waterworks in 1893; it has been out of service since February 1990. The no longer used water basins now serve as resting and breeding grounds for birds such as the little grebe. The use and development of the Elbe island has so far failed due to unfavorable location factors and the different interests of those involved. In the north there is a small boatyard. Hamburg Wasser opened the Kaltehofe water art on September 18, 2011 on the site of the former Kaltehofe waterworks. It is considered a mixture of industrial monument, museum and nature trail.