Editing CASTLE Base

{{Status|Canon}}
[[File:Reach map.png|thumb|300px|The location of CASTLE Base on Reach (identified here as "CAS").]]
'''CASTLE Base''' was an [[Office of Naval Intelligence]] underground facility located within the [[Reach FLEETCOM Military Complex|FLEETCOM Military Complex]]{{Ref/Novel|Id=TFoR29|TFoR|Chapter=29}} in [[Csongrád]]{{Ref/Generic|Heading=[[Data Drop]]|Subheading=[[Data Drop/Three]]|Detail=[[Data Drop/HABA]]}} on the [[human colonies|human colony]] of [[Reach]].

==Description==
CASTLE Base was hidden two kilometers directly underneath [[Menachite Mountain]], part of the [[Highland Mountains]] in the [[Viery Territory]].{{Ref/Note|The planetary map of Reach that comes with the [[Halo: Reach Limited Edition]] has "CAS" marked in the central mountain range of the Viery Territory. Judging by how SWORD Base's location is marked a similar callout "SWO" and Visegrad as "VIS", this places CASTLE Base in the Viery Territory.}} Protected by massive amounts of granite, reinforced concrete, plates of [[Titanium-A armor]], and [[EMP]]-hardened metal,{{Ref/Novel|FS|Chapter=11|Quote=Although he barely felt the descent, Wagner knew he had dropped three kilometers into the planet, through solid layers of granite, reinforced concrete, plates of Titanium-A, and EMP-hardened metal. None of this made him feel any safer, though; ONI's research facility on Reach had the same setup, and it had not done those poor bastards any good.}} it was virtually bombproof, well defended, and nigh-impenetrable.{{Ref/Novel|TFoR|Chapter=25|Quote=Castle was a massive complex, two thousand meters below the granite protection of the Highland Mountains — bombproof, well defended, and impenetrable.}}

[[Catherine Halsey|Dr. Catherine Halsey]] had an office in CASTLE Base's Omega Wing, as did [[Colonel]] [[James Ackerson]]. The [[SPARTAN-II program|SPARTAN-IIs]] were familiar with CASTLE Base, some of [[SPARTAN-II training|their training]] having taken place in the base{{Ref/Novel|Id=FS14|FS|Chapter=14}} as well as the abandoned mine tunnels around it.{{Ref/Novel|TFoR|Chapter=8}}

==History==
===Origins===
The complex that would later become CASTLE base was originally a [[titanium]] mine, but was closed down in the [[2520]]s or [[2530]]s{{Ref/Note|''Halo: First Strike'' describes the mine as having shut down two decades before the Fall of Reach, placing it in the 2520s-2530s.}} after the mine breached the [[Forerunner]] [[Menachite portal complex|complex]] below. The mine would be used for storage for several years before being put into action by the Office of Naval Intelligence.{{Ref/Novel|FS|Chapter=11}}

===Creation of Cortana===
On [[2549|November 7, 2549]], Dr. Halsey transferred and authenticated a brain specimen excised from one of her [[flash clones]] onto AI matrix strata, completing the initiation sequence within normal quantum flux tolerances. This artificial intelligence called herself [[Cortana]].{{Ref/Novel|Dr. Halsey's personal journal|Chapter=November 7, 2549}}{{Ref/Level|H5G|Osiris}}{{Ref/YouTube|MX8DKNh-iDc|Halo|Spartan Chatter: Shadows of Reach|T=868|D=29|M=01|Y=2025}}

===Fall of Reach===
{{Main|Fall of Reach|Raid on Reach}}
During the [[Fall of Reach]], the base was [[Delta-Red]]'s fallback position. [[William-043]], [[Vinh-030]], and [[Isaac-039]] arrived there. They were soon joined by [[Frederic-104]] and [[Kelly-087]]. There, they discovered Dr. Halsey, who had remained behind to initiate [[Operation: WHITE GLOVE]], destroying the base to prevent the [[Covenant]] from acquiring advanced UNSC technologies.

When the Covenant forces breached the base, Dr. Halsey was forced to put [[Operation: WHITE GLOVE]] into action, destroying the base and deleting her [[Artificial intelligence|AI]] assistant [[Kalmiya]]. This prevented the Covenant from gaining any intelligence from the base. Halsey and the Spartans then retreated into the dangerous titanium mines below, and later to the Forerunner complex, where they discovered a powerful [[Forerunner crystal]].

===Return to CASTLE base===
{{Main|Operation: WOLFE}}
In [[2559#October|October 2559]], Blue Team once again returned to CASTLE base seven years following the base's destruction. Following the emergence of the [[Created]] led by [[Cortana]] and the subsequent [[Created conflict|conflict]], Blue Team were ordered to breach the rubble of CASTLE and recover assets from Halsey's abandoned laboratory, believed to be key to defeating Cortana's forces. Despite the destruction of the base itself, the lab survived, guarded by a subroutine that [[Kalmiya]] had left behind to protect the cryo-vault. With some difficulty, Blue Team succeeded in extracting the assets back to the {{UNSCShip|Infinity}}.{{Ref/Novel|SoR|Chapter=??}} Using what Blue Team had recovered, her surviving cloned brains from the creation of Cortana, Halsey was able to create [[the Weapon]], a copy of Cortana capable of locking her down for deletion.{{Ref/Game|HI|HINF:Audio log#Recovered Files 2|UNSC Audio log|Detail=Recovered Files #04 - The Weapon}}

==Known sections==
*'''Level Aqua'''
**Section Lambda
***Armory
*'''Level Scarlet'''
**Omega Wing
***Dr. Halsey's office{{Ref/Reuse|TFoR29}}
**Medical wing
***Cold storage facilities
***Surgical bays
*'''Level Lavender'''
**Section Sigma
***Elevator shaft{{Ref/Reuse|FS14}}

==List of appearances==
*''[[Halo: The Fall of Reach]]'' {{1st}}
*''[[Halo: First Strike]]''
*''[[Halo Wars]]'' {{Mo}}
*''[[Halo: Reach]]'' {{Mo}}
**''[[Dr. Halsey's personal journal]]'' {{Mo}}
*''[[Halo: Mortal Dictata]]'' {{mo}}
*''[[Halo 5: Guardians]]''
*''[[Halo: Shadows of Reach]]''
*''[[Halo Infinite]]''
**''[[Winter Update]]'' {{Mo}}
*''[[Halo: The Television Series]]''
**''[[Solace (TV Series)|Solace]]'' {{C|Map-only}}
*''[[Halo: Empty Throne]]'' {{Mo}}

==Notes==
{{Ref/Notes}}

==Sources==
{{Ref/Sources}}

{{Office of Naval Intelligence}}
[[Category:UNSC military bases]]
[[Category:Reach locations]]