Kuh Qaen castle or Ghal'eh-Kuh of Qa'en (Persian: قلعه کوه قائن), also known as Husayn Qa'ini Castle (قلعه جسین قائنی), is a historical castle located in Qaen County in South Khorasan Province, The fortress dates back to the Ismailis of the Alamut Period.[1][2] It was one of their most important strongholds in Quhistan.
| Kuh Qaen castle | |
|---|---|
قلعه کوه قائن | |
 | |
 | |
| General information | |
| Type | Castle |
| Town or city | Qaen |
| Country |  Iran |