Orvieto Underground
There are several thousand caves located beneath Orvieto, of which only 2 are open to the public. ‎- Ken Morley
A system of subterranean cisterns and wells, and a steady supply of pigeons raised in chambers with access to the bluff walls, made the city near siege-proof. http://www.atlasobscura.com/places/orvieto-underground ‎- Ken Morley
I can verify the pigeon is pretty good! ‎- Ken Morley
کبوتر خانه جهت جمع آوری کود ‎- Mamad
@mirzaie I'm sure they used the manure for their plants. Nothing wasted. :) ‎- Ken Morley