Optional
Deity
What you will always get - this was in previous editions of Civ as well - is that the AI simply has more units to start with, so more chances to mop up those ruins.
I'm not sure whether the contents of the ruins deteriorate when you go up level, this was the case in Civ III, but I haven't seen any indication of this in Civ 5.
I'm not sure whether the contents of the ruins deteriorate when you go up level, this was the case in Civ III, but I haven't seen any indication of this in Civ 5.