Ubar, the Atlantis of the Sands

The account

Ubar, the city the Quran says was buried in sand for its sins, was hunted for centuries until satellite radar traced old caravan roads to a ruin over a collapsed cavern in the Omani desert.

Leads, where the trail points now

• The strongest lead has already been followed: satellite radar traced old caravan roads converging on Shisr in Oman, where a ruined fort over a collapsed limestone cavern was excavated in the early 1990s.
• Whether Shisr is the Ubar of legend is disputed, so the open work is archaeological interpretation rather than searching.
• The Rub al Khali around it is vast and barely surveyed; other caravan stops may still lie buried in the sand.