Bactriahistorical region in Central Asia / From Wikipedia, the free encyclopedia Bactria is a region in Asia. It is centered around the city of Balkh, in Northern Afghanistan. It is north of the Hindu Kush, and south of the river Amu Darya. Zoroaster might have been from this region. This short article about Asia can be made longer. You can help Wikipedia by adding to it. Greco-bactrian kingdom, when it was biggest.