The Isenberg is one of the best climbing spots in the Ruhrgebiet. It contains roughly 70 routes in all grades. The protection is pretty good and there is a nice meadow to lounge out. With 25 minutes, the approach isn’t too short for sport climbing standards. But it is pretty beautiful, so no need to worry. Last but not least, the spot is child friendly.
A fun fact is that the Isenberg used to be a boulder spot. It needed many hours of voluntary work by the local climbers to dig the walls out deeper and transform it to a climbing spot. By now, the Isenberg climbing walls reach 16 meters. Nearly the same amount of work was needed to secure loose rocks in the face. It is a nice example of what the climbing community is capable of doing.