Back in the ealy years of 3rd edition, a ST friend of mine ran an little adventure that he sure, was from the Wizards website. The adventure was about a tower which appears every 100 years or so. The tower is a lot of black/white good /evil themes, including some half celestial/half fiendish monks.
Sorry its a bit vague, but its been a while since Ive played it ! We were hoping to find the adventure again !
I can't recall a published adventure that your referring to so he might have used an adventure found HERE? If not, well this is still a great resource to use.
I know of three structures which periodically appear and disappear. There's the Impossible Palace of the Silver Domes from (I think) Kara-Tur, and the Palace of Skulls and Caer Allisynn, both from the Moonshaes. I don't know if this helps any, but maybe this will aid in your search or jog someone else's memory.