Fort aan de Winkel was built in 1895 as an earthen defence work. As was common practice in those days, the initial structure was a sandwork to allow the soil to settle. It took five years before the soil was considered stable enough for a concrete fort. The sandwork was designed as a defensible earthwork to defend the capital in the interim, with a concrete fort due to be added later. However, the inundation area in front of Fort aan de Winkel was so easy to defend that the building of the concrete fort was deemed a very low priority.