Characterized with a volcano and a Lake in its vicinity, the royal ensemble of Takht-e Soleyman has hosted the remains of palaces and royal structures dating back to the Sassanian Dynasty (3rd – 7th century AD). Thanks to its location, the area found a strong symbolic value for the Zoroastrian Sassanids, it became the most important sanctuary of Zoroastrians, believers of one of the first monotheistic religions of the world. The 10-hectare property in West Azerbaijan Province was inscribed as a UNESCO World Heritage List Site in 2003.