The Kiiu tower stronghold, also known as Monk Tower, is one of the Baltics' smallest residential fortifications. It was commissioned by Ferdinand von Tiesenhausen in 1517, and built by the monks from the neighbouring monastery in Kolga. It was partly destroyed in the Livonian war. Later, the tower was used as a maintenance building. In 1973, it was renovated to accommodate a youth club. Currently, the fortress serves as a cafeteria.