The Great Pyramid of Egypt is an enigma, but two of the most mysterious parts of this colossal construction are the so-called well shaft and the grotto, more crudely constructed than any other part of the pyramid with a function that, like most parts of the pyramid, is largely misunderstood or misinterpreted. In this video, we look at the ideas around the well shaft and the grotto and I explain how it is an intergral part of the pyramid water pump hypothesis put forward by engineer, John Cadman.