Ubar may refer to: Ab Bar A legendary land in southern Arabia, often referred to as Atlantis of the Sands, which is considered by some to be the same as: Iram of the Pillars Archaeological site of Shisr The Wabar or Ubar craters, near the lost Arabian city U bar, a letter of the Latin alphabet, that's formed from U with the addition of a bar: Ʉ, ʉ. μbar, a unit of pressure