The fire tower is definitely worth a visit! In good weather you have a great view over the Haard, the Ruhr area and the Münsterland.
However, since the respective platforms and platform are made up of bars, one should not have a problem with high altitudes.
The fire tower Farnberg stands on the third highest elevation of the Haard (136.4 m). The tower is 38 meters high and has 179 steps and is 171 meters above NHN. (Https://de.wikipedia.org/wiki/Farnberg_(Haard)#Feuerwachturm_Farnberg)
Great view! There is nothing more to say .... - but: nice way, the steps (light grid) are backed with metal, for all who can look down so bad 😉 Unfortunately, not all intermediate platforms, for all who can look down badly. As you look better then in the distance - but that's exactly why you climb on such a tower - and to look down. 😉 And the small hike through the forest there is also worthwhile. You can park very close to "Mutter Wehner"