Researchers from Cairo University and the Technical University of Munich (TUM) have located two air-filled spaces within Giza’s Menkaure pyramid that hint at a possible secret entrance. Their findings were published in the academic journal  NDT & E International . The Menkaure pyramid is the smallest of the three main pyramids on Cairo’s Giza plateau. Built for the Fourth Dynasty ruler Menkaure, it was completed in the 26th century BC. It was excavated between 1906 to 1910, but has not been fully explored since then. Related Articles The structure is distinguished from its two larger neighbors by having been partially clad in red granite blocks, rather than white limestone. An unusually smooth area on its eastern facade has long intrigued researchers, due to its resemblance to a similarly polished section at its north-facing main entrance.…