You're only allowed one grand mosque. Same goes for a cathedral if you're Catholic, and for a few of the other buildings. You can build a grand mosque in another location if you destroy the one in Arabia, though there's only one good reason to do so that I know of. If you're playing as the Turks you need a grand mosque as a prerequisite to the military academy, which you need to build janissaries. You can only have one grand mosque, but the same does not go for military academies, so you can build the mosque, then the academy, then destroy the mosque and build it elsewhere to get an academy there as well, so you can have multiple janissary farms.
Bookmarks