I drive to the castle very often, only 6 km from my home. Then from Kalten Wangen on the mountain ridge on the Way of St. James to the castle, there enjoy the fabulous views, there is also a restaurant with garden seat. There are also pension rooms. From there you can then continue to Rheinheim or Lienheim, all the way to the Rhine, where then again 1000 possibilities arise, e.g. in Switzerland over Glatttal direction Bülach, or better the trail for demanding expectations of Eglisau with a stopover on the north side of the Rhine to the Rhine Falls to Neuhausen (Schaffhausen) From the castle to the Rhine Falls but you should be fit, and expect 50km. Beginners should take the road is also 20km less. In my profile the journey from Hohentengen to the Rhine Falls can be found as GPX.