Turns out the builders of a nearly 5000-year old set of structures have a great deal of wisdom to offer to the current day construction industry. The mysteries surrounding the building of the Great Pyramids of Giza have perplexed scientists for centuries, but a research team out of Drexel University offers some answers. Evidence indicates that parts of the Pyramids were built using an early form of concrete. Blocks were cast–not carved–using a limestone concrete. Replicating the recipe for this ancient technique could provide a cost-effective, easily accessible, long-lasting, and much more environmentally friendly alternative to current cement building materials.