The Onze-Lieve-Vrouwetoren, nicknamed Lange Jan, is a church tower in Amersfoort. The Late Gothic building is 98.33 metres tall and reaches high above the inner city. It is one of the most eye-catching monuments in town and the third highest church tower in the Netherlands. The church that belonged to the tower was destroyed by a gunpowder explosion in th…The Onze-Lieve-Vrouwetoren, nicknamed Lange Jan, is a church tower in Amersfoort. The Late Gothic building is 98.33 metres tall and reaches high above the inner city. It is one of the most eye-catching monuments in town and the third highest church tower in the Netherlands. The church that belonged to the tower was destroyed by a gunpowder explosion in the 18th century.