Roman Castle Irgenhausen

The origins of the fort are controversially debated. One theory dates its construction to the time of Emperor Diocletian around 294/295 AD, concurrently with similar installations. Another assumption is based on coin finds from the reign of Valentinian I (364–375 AD) and suggests an erection around 370 AD or a comprehensive renovation of existing structures. It is undeniable that the fort was evacuated shortly after 400 AD and later destroyed during Alamannic invasions. Early stone finds were made, but it was not until 1897, when material was to be extracted for a factory building, that the Roman origins were recognized. The Antiquarian Society of Zurich acquired the site in 1898 and conducted archaeological investigations until 1908, during which the walls were restored and conserved. In 1909, the fort was placed under federal protection. In 1957, the site became the property of the municipality of Pfäffikon.