Bactria

Bactria is the ancient name of a historical region located south of the Amu Darya and surrounding the district of Gandhara (said to be its “crown jewel”), one of the ancient civilizations of Iranian peoples, covering the modern-day flat region that straddles Pakistan, Afghanistan and Tajikistan. Ancient Bactria was in Western Pakistan, present-day eastern Afghanistan, south of the Parmir mountain range and the Amu Darya.
Furthermore, Bactria was the birthplace of Zoroastrianism, and later also hosted Buddhism before becoming Muslim after the arrival of the Rashidun and Umayyad Caliphates in the 7th century. Bactria was also sometimes referred to by the Greeks as Bactriana.