grotto

From ancient cisterns and water systems to mysterious caves, underground crypts, subterranean temples and even entire cities built beneath the earth, what our ancient ancestors have achieved is both mind-boggling and breathtaking. Here we feature ten incredible ancient subterranean structures whose construction is awesome. Party in the Historic Paris Catacombs, But Don't Tell! (Video) Discoveries of Ancient Underground Cities Around the World The Amazing Subterranean Structure of the Basilica Cistern Hidden beneath the city of Istanbul, Turkey, are hundreds of ancient cisterns that stored and supplied water to its inhabitants in the ancient past. The largest of these is the Basilica Cistern. So spectacular is the cistern that one could easily mistake it for a sacred subterranean temple. The Cistern