Oops! I forgot to tell you some important information regarding the origin of the landscape here. The Wageningse berg was formed during the second last ice age (Saale glaciation), when glaciers pushed soil material upwards to form push morenes (stuwwallen). But what material did they push up? They pushed up the fluvial (deposited by water) deposits of the rivers in the landscape. These have a very heterogeneous composition, with layers of gravel, sand, silt and clay. When the glaciers pushed this material to form the Wageningse berg, this heterogeneity was increased even more by the mixing of these layers. This is why you can find gravel on top of the hill (which would otherwise be a weird location for stones).
The location that you are standing on now has a fine sandy texture with relatively much loam in it (check this!). Psst! if you want to check if the soil is loamy, you get a bit of soil material with a light colour (not with much humus in it) and you rub it on the back of your hand, when your hand gets beige/brown after you’ve scraped the soil off, there is loam present! See the picture!