Ketelvierth Observation Tower, Wooden observation tower in Großenaspe, Germany.

The Ketelvierth Observation Tower is a wooden structure in Großenaspe standing about 16 meters tall above the Schleswig-Holstein landscape. The timber frame includes multiple platforms at different heights that allow visitors to view the surrounding Kreis Segeberg region.

The tower was erected in 2003 as part of a village development programme on the Ketelvierth, a hill 73.2 metres high in the municipality of Großenaspe. It originally stood twelve metres tall; in 2010 it was raised by a good four metres so that the view would again reach over the treetops, bringing its present height to 16.4 metres.

The tower stands on the Ketelvierth, a 73.2-metre hill that is the highest point in the area around Großenaspe. It was erected in 2003 as part of a village development programme, and in 2010 it was raised by about four metres so that walkers could again see over the treetops. The name Ketelvierth refers to the hill itself.

The tower is open year-round and can generally be visited without restrictions. The multiple platforms allow visitors to enjoy views from different heights and choose their preferred vantage point.

The tower serves as a local reference point in Großenaspe and is popular with hikers exploring the flat northern German landscape. The wooden construction provides stability even on windy days and allows safe viewing.