The Great Sphinx is a tomb in Egypt (Act II), accessed from the Giza Plateau. You will find the Hand of Balance here, one of the two quest items requested by Imhotep back in Memphis. Throughout the tomb you will also find more or less valuable treasure containers plus a Majestic Chest in the final chamber. At the entrance there is a Rebirth Fountain. Progress clockwise through the rooms to find another Rebirth Fountain and a ramp leading further down to a large door, where some sort of boss-battle awaits you. The door closes when you enter the room and opens again when the battle is over.