Belvedereturm, Observation tower in Bad Nenndorf, Germany.

The Belvedereturm is an octagonal stone tower on the Strutzberg, the northwesternmost hill of the Deister, at 198 m above sea level near Bad Nenndorf. Its outer wall bears the Hanstein-Knorr family coat of arms with the year 1852. A steel structure added in 1987 tops the tower, which is reached by just under 130 steps.

A nobleman named Freiherr von Hanstein-Knorr commissioned its construction between 1850 and 1852, paying for it entirely with his own funds. Local spa visitors of the time also contributed support to the project, making it a shared endeavor.

The tower's name comes from the Italian "bel vedere", meaning beautiful view, a phrase used for vantage points across Europe. On the outer wall of the octagonal stone shaft, the Hanstein-Knorr family coat of arms is set beside the year 1852, marking the year the tower was finished. The European long-distance path E1 passes directly by the tower, so walkers on that route see the crest as they go.

The climb to the viewing platform involves roughly 130 steps to the top of the structure. The site sits on multiple hiking trails, including the European long-distance footpath E1, making it simple to combine a visit with a longer walk through the area.

A steel framework was added in 1987 to reinforce the original sandstone structure and increase its height. This renovation allows for even better sightlines across the landscape below.