Ingo-Valgma:
Former Kiviõli oil shale mine, Estonia
Ingo-Valgma:
Former Kiviõli oil shale mine, Estonia
Ingo-Valgma:
Former Kiviõli oil shale mine, Estonia
Ingo-Valgma:
Aidu karjääri lubjakiviga (aherainega) kaetud Kiviõli poolkoksimägi / Kiviõli semicoke hill in Estonia, covered with waste rock from Aidu oil shale open-cast mine
Ingo-Valgma:
Kiviõli. Siin asus Sala karjäär ja Kiviõli kaevandus / Kiviõli oil shale mining area in Estonia