Archaeology used to be concerned mainly with ancient remains; today it may also encompass the study of relatively recent material culture.
I will call what I sometimes do ‘Sylvan Archaeology’. Here is a case in point: Along Hakenstakendreef is this concrete post seemingly stuck in the stump of a tree. I have indicated its position on the map below.
This concrete post dates from the time when there was a railway line, a spur, running from the Brussels-Namur mainline to the nearby Hippodrome. It, along with others, formed a barrier to stop the public straying onto the tracks on racedays. Or at least that’s my interpretation.
If you look carefully, more so in winter, your eyes can follow the curve of the railway. I have attached a portion of Stevens’ 1917 map indicating it. A telling clue is the age, or rather lack of, the vegetation.