This 15th-century Gothic tower is Amersfoort's defining architectural icon. It's the only surviving component of a church that was otherwise destroyed by an unfortunate gunpowder blast in 1787. To climb the 346 steps, buy tour tickets from the nearby tourist office.
You don't need a ticket to wander into the base and look down, watching two crosshairs mesh indicating Amersfoort's location on a map of the Netherlands. The tower traditionally marked the exact centre of the country and is still used as a reference point in the Dutch geographical coordinate system.