The Koppelpoort gate in Amersfoort, Netherlands. Taken by Wikimedia Commons user Bert.

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The Koppelpoort is the name for a medieval gate located in the Dutch town Amersfoort. The gate was built between in 1425 as part of the second city wall defenses, and it helped to repel an attack on the city in 1427. Dutch raddraaiers, or “wheel-turners,” would daily open and shut the gate centuries ago when it was an active defense mechanism.

Amersfoort is the second largest city of the province of Utrecht. Its central location in the country makes it one of the largest railway hubs, and east-west lines connect easily with north-south train lines.