I haven't gotten to use it yet, but I built a two-story temple of Pelor out of white poster board, scaled to the D&D minis that we use in our 3.5 game, which will be used in an upcoming adventure.
A recent adventure used a similar castle I had made out of cardboard (reused it, actually; I added an upper level to the castle structure I had originally built over a year ago for a completely different adventure). The original cardboard castle was a keep on Oerth that the PCs had to assault; this "upgraded" version was a demon's castle on his level of the Abyss that the PCs - their memories having been downloaded into warforged bodies that would only last for 24 hours - had to attack and infiltrate so they could destroy the magic mirrors imprisoning the PCs' reflections. Only by smashing the mirrors and freeing their reflections could they release the hold the nalfeshnee demon held over them, as the mirrors not only allowed him to scry upon their every act, but could also be used to summon them across the planes to his layer of the Abyss.
Johnathan
A recent adventure used a similar castle I had made out of cardboard (reused it, actually; I added an upper level to the castle structure I had originally built over a year ago for a completely different adventure). The original cardboard castle was a keep on Oerth that the PCs had to assault; this "upgraded" version was a demon's castle on his level of the Abyss that the PCs - their memories having been downloaded into warforged bodies that would only last for 24 hours - had to attack and infiltrate so they could destroy the magic mirrors imprisoning the PCs' reflections. Only by smashing the mirrors and freeing their reflections could they release the hold the nalfeshnee demon held over them, as the mirrors not only allowed him to scry upon their every act, but could also be used to summon them across the planes to his layer of the Abyss.
Johnathan