layers of stone blocks at the base of the wall were laid around 20 B.C., when Temple Mount and the Jewish Second Temple were rebuilt by the Roman "client-king" of Judea, Herod I. A new app for smartphones and portable virtual-reality headsets, called Lithodomos VR, offers a view of the Western Wall and other historic sites in Jerusalem as they looked at the height of the city's splendor in the first century A.D.