Until 1961, behind all the undergrowth was the Pforzheim velodrome. You can still guess the dam of the steep curves.
In 1957 and 58, for example, Rudi Altig drove legendary races here.
The track was later filled with "some" rubbish and everything is done to ensure that you don't come onto the site."A little information" about the races on the track can be found at:
ws-pforzheim.de/standortmarketing/events-aktionen/freizeit-sport/vaude-trans-schwarzwald/radsportgeschichte-pforzheim.html (unfortunately error 404!?) and
pfenz.de/wiki/Radrennbahnto the garbage :
pz-news.de/pforzheim_artikel,-Radrennbahn-unsuitable-No-expansion-der-Gartenanlage-_arid,1230363.html

You really can't see anything anymore, only the heaped-up curves can still be guessed between all the trees and bushes.
The PZ from August 6th, 2022 happened to contain a historical picture of a race in 1939, see pictures for the highlight.

you can't really see anything anymore, at least in spring/summer when the trees/bushes are in leaf.