definitive histories of the dead sea. and like any good guide, she has to start our quest by checking a map. and long before google, there was the floor of st. george's cathedral in jordan. >> this is to the north. the jordan river flowing into the dead sea. >> 1,500 years ago, greek orthodox artists used tiny pieces of tile to create this strikingly accurate map of the middle east. >> the famous fish who's high-tailing it back up the jordan river. he's tasted the dead sea water. he knows it's a mistake, and it looks like he's trying to warn his friend to turn around as well. >> swim away! >> this floor turned out to be a lot more reliable than all the christian pilgrims who spread dead sea horror stories through the ages. like the tales of serpents so deadly, if they bit a horse, it would kill the rider. >> maybe this was, in fact, intended to keep you away because this was, after all, the site of sodom and gomorrah. and who knows if the cities were