Monreal-Resch
Philipsburg is Lowenburg's neighbor.  There is not much left of this castle, and recent work (as of 2008) has begun to prevent further decay.  Nevertheless, it is worth the walk to visit.
Philipsburg from the town below.  Unlike Lowenburg, the tower is more for observation and to coordinate the defense of the castle rather than to withstand a lengthy siege.

Below, a view from within the inner ward showing the base of the tower and what used to be the palas.
Left, a view of the top of the tower showing the overlap that once supported a roof.  Today the tower is completely hollow.

Note also the shape of the tower, having a modest peak on the left.
A view of Philipsburg from the trails between the two castles.

Below, another view through the narrow streets of Monreal, with Philipsburg beyond.
A view of the crumbling wall and the tower.

Below, two views up the length of the tower, which once had wooden steps wending their way upward.  There appears to be no indication that the tower had stone steps as I could not find evidence of their footings in the wall.  There is evidence of slots for several platforms and for the roof, which may have also been of wood.

If you look very carefully at the lower left photo, you can see a bricked-in doorway (near the bottom of the picture), which was probably the original entrance into the tower.