More pictures of Amersfoort here.
The Koppelpoort is a medieval gate in the Dutch town Amersfoort. Completed around 1425, the gate combines land- and water-gates, and is part of the second city wall of Amersfoort, which was constructed between 1380 and 1450. The gate was built between 1380 and 1425 as part of the second city wall. The whole wall was completed around 1450. The gate was attacked in 1427 during the siege of the city. This attack was repelled.