Fortaleza Califal de Gormaz
San Esteban de Gormaz, Spain
The Castle of Gormaz, in the province of Soria, Spain, is strategically situated on a high promontory overlooking the small Castilian village, San Esteban de Gormaz, and the Duero River with its expansive flatlands. It was constructed in 956 under the reign of caliph Al Hakam al-Mustansir, (Al-Hakam II) to further fortify Moorish territory and as a base for military offenses into northern territories. The oldest and largest citadel in Western Europe, it measures 390 meters in length and up to 60 meters in width. 
 
Built with ashlar carved stone.Divided into two areas by a moat:the fortress and the walled enclosure where the soldiers and the cisterns were.In the fortress there were seven towers out of which the Almanzor and the Keep are the most noteworthy.It also had an underground reservoir and an important armoury.  (http://www.spain.info/en_US/que-quieres/arte/monumentos/soria/castillo_de_gormaz.html)
Its most prominent detail is its original entrance that features a double horseshoe arch. After being repeatedly sacked by both Arab and Christian armies throughout its early history, it now remains unused and in the property of the local municipality.

Sources:

Goodwin, Godfrey. Islamic Spain, 121.  London: Penguin Group, 1990.

Robertson, Ian.  Blue Guide Spain: The Mainland, 341. London and Tonbridge: Ernest Benn Limited, 1980.

"Gormaz." Castillos de Soria Website. http://www.castillosdesoria.com/gormaz.htm. [Accessed February 14, 2007]
Location
San Esteban de Gormaz, Spain
Images & Videos
Associated Collections
Events
ca. 956/345 AH
Style Periods
Variant Names
Fortaleza Califal de Gormaz
Hisn al-Ghurmaj
Alternate
Fortaleza de Gormaz
Alternate
The Fortress of Gormaz
Alternate
Castillo de Gormaz
Alternate
Building Usages
castle
military