Ohlyturm on the summit of Felsgberg. From here you can hike (especially recommended the Felsenmeer) and biking (especially recommended: Gambolimbo and Felsberg-Downhill (right from the Ohlyturm keep right)
There are many reasons to bike on the Felsberg: the Felsenmeer, the Ohly Tower, the beautiful trails towards Reichenbach and to Balkhausen. One of the nicest is the stop on the terrace of Ada's Buka. Really good food at absolutely fair prices!