Neudahn
As can be seen by the right photo, the setting sun admirably highlighted the sandstone construction of the castle.

Below, I'm not sure about the image on this window sill.  My instincts tell me that this is a recreation and not authentic, though possibly based on something historical.
Below, a view of the acute angle bastion from above.  This section has clearly been rebuilt due to the nature of the symmetrical sections and evenly aligned walls.
Left, one of the spiral stairways.  These have been rebuilt, though at least on the basis of the original design.  However, evidence along the cylindrical wall suggest that the stairs do not precisely follow the same layout.


Below left, one of the vaulted ribbed ceilings within the interior.  Neudahn is a unique castle in that it employed several levels of stone floors supported by such ceilings, in large measure avoiding the wholesale use of wooden joists and floors.  While making the castle more durable and less pervious to bombardment with flammable missiles, it also made the castle extremely expensive.

Below, more ribbed vault ceilings.  These ceilings have been obviously restored, but the portions did exist prior to the restoration, such as the section in the background. 
Below, two stairway towers, one going down (left) and the other going up.  By creating separate stairways, the builders helped to spread the static load.  Building one stairway would have placed excess load on the foundation, possibly causing the stairway tower to settle and separate from the rest of the structure.

Unfortunately, somebody had to spray paint something on the door frame.
Left, a rebuilt stairway that would have been within the lower castle.

Below, the hole in the stone was probably used as a pivot for the doorway into the lower castle.  The stairs are heavily worn but extant.  These are authentic items from the castle's past.
Right, one of the stairways leading into the depths of the lower castle.  Some repair work has been done, but the basic structure appears to be of genuine early construction.