Digging deep: 15 ancient ruins you might not know
(CNN) -- Ancient sites open your mind to just how old "old" can be and how sophisticated our ancient ancestors were in devising their artistic, engineering and construction methods. You'll never equate "ancient" with "primitive" again. You don't need us to call your attention to the Colisseum in Rome or the pyramids in Egypt. So, like archaeologists, we're digging deep for a list of lesser-known ancient ruins. We're abiding by the Merriam-Webster dictionary definition of "ancient" as history up to the fall of the Roman Empire in 476 AD. That means you won't find New World sites on this list. (We'll follow up with that list soon.) Our definition of "ruins" includes some sites that are mere shadows of their glory days and others that have been protected or preserved since, virtually, the beginning of civilization. We recognize that some of these destinations are not recommended for tourists at the present tim