>Put it this way: you put your walkable gardens on top of christian cathedrals, I build up tennis courts on top of mosques and swimming pool on top of synagogues.

Sure, why not? They're just buildings, and that sounds like fun.

And I'm pretty sure that as far as the Christian faith is concerned, one isn't supposed to put value in the temporal universe or its constructs, and a grand cathedral is as meaningless to God as a mud hut.