Madain Saleh is the southernmost outpost of the Nabateans; this
    tomb is from the first century, CE.  Note the roughly chiseled
    walls, different from the outside smoothly carved features, KAUST
    arranged this CAVEcam expedition as part of a training session
    conducted by Dick Ainsworth, Tom DeFanti, and Dan Sandin, for
    KAUST Visualization Lab team members.