The Koppelpoort is a city gate in Amersfoort. It is a combination of a land and water gate. The name is probably derived from the East Middle Dutch word coppel which means common meadow. The area outside the Koppelpoort was a common area. The name, therefore, does not indicate that the gate has two functions.
The Koppelpoort could be closed by means of a double treadmill. It still functions.
Above the watergate is a mezekouw, a wooden extension from which glowing pitch could be thrown down.
Between 1645 and 1778 there was still a front gate in front of the Koppelpoort. This may have been designed by the Amersfoort architect Jacob van Campen.
The gate was built between 1380 and 1425 as part of the second city wall. The entire wall was completed around 1450. The gate was attacked in 1427 during the siege of the city. This attack was repelled.
The gate was opened and closed every day by wheel turners. The wheel turners (minimum 12 people) were picked up in the morning and evening by several guards. It was a very dangerous job: if they did not start running at the same time, one could fall and drag the rest, often with fatal consequences. Before the shot could go down it had to go up first, to take out the iron pins that were in it. Only then could it go down. As the shot goes down, walking in the wheel becomes easier and faster, many people stumble and break limbs.