Qanat of Gonabad
Qasabeh Qanat of Gonabad · Kariz Kai Khosrow
Achaemenid to Sassanian (~700 BCE – 300 CE)·Persian (Achaemenid, Sassanian)·🇮🇷 Razavi Khorasan, Iran
About
About Qanat of Gonabad
Possibly the oldest and deepest qanat in Iran, the Qasabeh Qanat of Gonabad extends 33 km with a mother-well 300 m deep — the deepest vertical shaft ever hand-dug. Twin parallel galleries ensure year-round flow of 150 l/s into Gonabad oasis despite 150 mm rainfall. UNESCO cites it as the masterpiece of Persian Qanat technology, continuously operated for 2,700 years.
Why it mattersPossibly the oldest and deepest qanat in Iran, the Qasabeh Qanat of Gonabad extends 33 km with a mother-well 300 m deep — the deepest vertical shaft ever hand-dug. Twin parallel galleries ensure year-
Open questions
Mysteries & theories
Mysteries
- 01How Achaemenid diggers achieved vertical precision with oil-lamp triangulation at 300-m depth
- 02Dual-gallery design – redundancy or aquifer stratification?
Theories
- 01Imperial Achaemenid investment to secure Khorasan route after Cyrus conquest
- 02Zoroastrian water veneration encoding hydraulic sanctity
Theories are interpretations, not findings. The seal above tells you how much scholarly weight the place carries.
History
How it came to be
- Built
- c.700–500 BCE (legendary Kai Khosrow era; archaeologically Iron Age)
- Period
- Achaemenid to Sassanian (~700 BCE – 300 CE)
- Culture
- Persian (Achaemenid, Sassanian)
- Purpose
- Deep qanat tapping alluvial aquifer for desert town survival
- Excavation
- Excavation ongoing
c.700–500 BCE (legendary Kai Khosrow era; archaeologically Iron Age)
Initial construction
c. 1208 CE
Abandonment
On the ground
Structures & features
34.3523° N · 58.6836° E · 1100 m · 2 mapped features
Mother Well (Cheh-e Mādar)
shaft300-m vertical shaft feeding twin galleries
34.3523° N · 58.6836° EOutlet (Mazhar) and Reservoir
hydraulic structureDaylight outlet with historical payab and ab-anbar cistern
34.3540° N · 58.6510° E
Gallery