This set is a good start for building parts, one of the first sets I got, back from my dark ages, and off e-bay, it was only 2€, lacking only some little plates, say a 1x3 and a 1x4, no shipping because I was able to go and get it.

Well, the surprise can be really surprising, if you manage to hide the skellie's arms, it can be achieved, I swear. Beside, the architectural structure is not very straightforward, espescially for the floor, wich can be dangerous for an archer to walk onto.
Mixed with another parts set like black monarch's ghost, you give it its barn doors, extend wall or make a tower up the doors with 45° wall sections, open the mausoleum's back, rip off the baseplate and put normal plates under the walls, add technic linking possibility, and you have a real modular wall section with gate.

It is a nice source of parts to modify forestmen's buildings, and back in the days, I think it was a nice set to start with castle theme too.