Hohenneuffen
There are plenty of places to walk to and explore, including some unique passageways to outlying battlements.  The photo below provides a good illustration as to how large this fortification truly was.
One set of passageways will take you along the side of the castle (right and below).  The photo on the right shows the battlements fairly open, but the construction indicated they may have only had vision slits or small windows.
A good portion of Hohenneuffen's walls have been destroyed.  As a result, it was necessary to erect steel barriers to keep tourists from wandering off the sides! 

The photo lower left shows the size of one of the turrets, with the barrier plainly visible.  The view from along the walls to any direction is excellent, if the weather is cooperating.  When I first arrived, it was misty, but it did clear up some later.

Below, a picnic area within the castle grounds.  Hohenneuffen has a nice little cafe with picnic tables nearby, making it a pleasant place to stop and relax, and just to enjoy the beauty of the Schwabische Alb!  While Hohenneuffen does get some tourists, most are Germans, and during the weekday it is only lightly frequented.
To the right, a view from Hohenneuffen to Burg Teck, which is to the east along the ridge in the foreground.  Teck is situated on the left side of the ridge, on the highest rise.