This SLP-Installer mod changes the useless "Church 4" square in the scenario "New units and objects template.scx" into a nice large castle from a Pre-Alpha version of AoK, which you can have permanently in the game and use anyhow you want in your scenarios.
NOTE: You have to have the scenario "New units and objects template.scx" in your AoK scenario folder in order to see this mod take effect. You can unzip the one in the mod's .zip file or: