of varieties of potato. >> it isis some of the finest stone work in all the empire. >> it goes in like a cork. >> butted here we have double sided rock and that is difficult. because then you have one single piece of rock -- >> that as to be perfectly square. >> exactly. that is the ultimate thing and nothing compared. >> these intricate plumbing systems are gravity fed, all carving in to the rock. feeding into baths, gutter systems. this is water that's been ruing for 6 or700 years. who knows if hyram bingham had had quote on quote discovered this place if stead, pumped