There's a chamber under the Sphinx's left paw. Textual evidence suggests it was an archive...a place where records were kept. This wasn't a search for the Hall of Records. Seismic data was used to study subsurface mineralogical changes. When the Sphinx's core body was freed from the bedrock, the rock started to weather. Minerals changed. Analyzing how deep those changes go reveals how long ago the Sphinx was carved. See more from Robert: https://www.robertschoch.com/ | Cosmic Summit