Naga's Castle is a winding spire made of stone. It sits precariously atop a mountain in the Kamalaku range, making the climb up to the fortress difficult. A single stone bridge leads to the portcullis, and each level has a large terrace protruding from it. This makes escape by any way other than flight very difficult.
Naga's large throne room occupies the top level and inside sits his golden throne, fashioned to look like the webbed gills on either side of his head.
It is unknown whether or not Naga or any of the other Baddies returned to this castle after Moo was defeated.