Strahlenburg
My photos of the outside of Strahlenburg date back to 1978.  I was hiking along the Bergstrasse, and went by the castle, but decided not to hike to it, as my primary objective was to hike into Heidelberg.  I finally visited the castle in 2008.  The tower is worth the visit, but there is not much else to see.  Furthermore, the restaurant is quite pricey.
To the right, a series of photos taken in 2008 showing the very tight climbing ladder within the Strahlenburg tower.  The keep is not the type where anyone could live for any extended period of time, but was clearly designed for a last-ditch effort to defend the castle.  The wooden structure of the ladder and platforms is naturally a fairly recent reproduction.  However, the platforms do conform to the tower's stone indents to support these.  There are seven unique levels to the top of the tower!