The forests on the Grebbeberg, near the town of Rhenen, the Netherlands. It is a c. 50 meter high hill in the centre of the Netherlands, pushed up by a gigantic ice sheet that partially covered the country during the fore last Ice Age. One side is formed by a steep cliff, as the hill had been cut away by the river Rhine over time. During the early middle ages, a castle was built on top of the hill, the earthworks of which still remain overlooking the river and the Betuwe plains beyond. These ramparts are the oldest structures visible on the hill, but archaeological evidence indicates the hill had been fortified as early as 2000 BCE. After the middle ages, the foot of the hill was heavily fortified as it formed the southernmost tip of the Grebbe line, a long line of inundations and fortifications, defending the rich western Netherlands from attacks from the east. The last time this line was put to the test was during the earliest days of the second world war, when a small contingent of poorly armed soldiers managed to keep a vastly superior force of SS at bay. Unfortunately inundations and trenches may work against infantry, but not against airplanes. The Netherlands surrendered after the bombing of Rotterdam and the threat to do the same to Amsterdam and Utrecht. Remnants of bunkers and trenches, as well as a military cemetery are visible remnants of this last stand.