A BURP is a Big Ugly Rock Piece... and there are quite a number of BURPs in this set. The set also adds in the wooden wall pieces and a large amount of greenery. The end result is that the fortress seems rather symmetrical and man-made when the intention is presumably supposed to be more organic in nature (pun not intended, e.g. forestmen sets). Again the door is weak - it would have been better if it was a rock that could have been rolled away. The "action feature" with the turning knob is interesting for the first time, but there are better uses for it than in this set. The catapault thing also seems rather distorted, thanks to the hidden chamber beneath it - why would anyone want to hide weapons inside a weapon of war? The flyer again seems to have a raft on his back as is common with most Ninja sets instead of something slick and lightweight. Overall the colours didn't clash too badly (although red and green on grey and brown is weird), but the design didn't live up to its potential. This is the worse big Ninja set of 1998.