the upper chambers of the big temple are a must see. so overseas members plan for a trip soon.
one aspect was the hollow dome within the vimanam of the big temple.
we could see that from the upper chamber only. the experts there say a two inch thick bat excreta later was removed from the 200+ feet high dome's inner walls. {that itself is a mammoth task} once that was done, the resonance and acoustic ability have increased .
in the original pre- nayak period the peruvudayar had this dome above him.so all the mantrams and devaram must have created astounding acoustics.
first the inner walls are not smooth seemed to have belt sort of lines i assumed the bats must be hanging from those small projections and so it was possible
bats are a perpetual problem in temples the odour and trash that they make . in many temples today they hang bunches of thorns to prevent their flying one innovation that i saw in a temple near tharangam badi( a fishing town) was that they had stretched a fishnet on 4 hooks at two ends of a passage and the gurukkal claimed it was 100% bat free.
but architecture also has its say just like mada koils have construction to preven elephant entry there are mandapams designed to prevent bats from hanging.