The Observation Tower is the result of a study into the optimal application of Ultra High Performance Concrete by a case study team comprising of UNStudio, ABT, BAM Utiliteitsbouw, and Haitsma Beton. Natuurmonumenten received the design as a gift from the case study team. Ultra High Performance Concrete differs from normal concrete as it has a very high density, contains steel fibres, and has an extremely fine grain structure.
Found on UNstudio.com.
