The Koppelpoort is a medieval gate in the Dutch town Amersfoort. Completed around 1425, it is a well-preserved example of medieval fortification. It is a combined land and water gate and is part of Amersfoort's second city wall, which was constructed between 1380 and 1450. The gate was opened and closed every day by twelve appointed raddraaiers, "wheel-turners". The wall was last restored in 1996.Photo: Bert Kaufmann