Construction beginning/end
The Crown of Krratin, among the oldest Frithitt-built structures in the world, is built during this time span.
Though dates vary and the native Krratin Frithitt claim it to have predated their arrival in the Vale (200,000 years before this time stamp), most archaeologists believed that the Crown of Krratin was built during this time period. The Kettket Frithitt allege that it was ruled by the sorcerer Saaf Salahan, who hailed from deep in the Underdark. It is not believed that this represents a real historical figure, however.