Observation tower Thurauen, Flaach

The project
Completed in 2025, the observation tower is located on the left bank in the direction of flow of the Thur, as seen from the Ellikerstrasse bridge, directly on the riverbank. At 15 meters high, it is an imposing structure, but it blends seamlessly into the floodplain landscape. There are platforms at heights of eight and twelve meters where visitors can observe nature and enjoy the panoramic view. The project originated from a master's thesis at ETH Zurich.

The construction method
The supporting structure consists of crossed rods. The inclination of the straight rods creates the impression that the rods are curved. This structure is called a hyperboloid. The two platforms are suspended from this hyperboloid. The spiral staircase stands separately.

The challenge
The delicate bars of the staircase cage did not allow for any load to be taken up by the platforms, so a structure had to be found for the platform without central support. The connections between the outer bars/supports were also challenging because the angles change on each step.

Project description Canton of Zurich