The Rosenborn is in fact regarded as the source of the Wohlrose. The Wohlrose is a river in the Ilm district and with 17.6 km the longest tributary of the Ilm. From here it feeds the Ochsenbacher pond and continues in the Wohlrose valley in the direction of Möhrenbach to then feed the Ilm via Gehren (where it picks up the Schobse) and Jesuborn near the Annawerk.