From then until 1812, when the intrepid Swiss explorer John L. Burckhardt rediscovered Petra, it was almost totally forgotten.
When the Swiss explorer rediscovered Petra, it was in terrible condition.
mnli hypothesis: When the Swiss explorer rediscovered Petra, it was in terrible condition. premise: From then until 1812, when the intrepid Swiss explorer John L. Burckhardt rediscovered Petra, it was almost totally forgotten.