The military watchtower is today one of the clearest manifestations of surveillance technology. As object and icon, it is one of few physical and tangible structures of surveillance that visualizes and concretizes the modern, digital surveillance of data. On a general level, the development of 20th-century military watchtowers can be seen as part of a technological development of different vision machines. These diverse technologies of vision use different forms of design and architecture and they create certain social, political and power-related conditions for the landscape and the human being. As a phenomenon of architecture and design, the watchtower can therefore be regarded as the foundation for the development of emerging structures of new 'vision machines' in the surveillance society. Thus, the watchtower stands out as the very symbol of historical and contemporary surveillance culture.