Toward a castle; in the direction of a castle (variant or plural form of castleward).
Variant or archaic plural/adverbial form of castleward, using the -wards ending (common in British English for directional words like backwards, afterwards).
The -wards versus -ward distinction is quirky British English: 'toward' vs. 'towards,' 'backward' vs. 'backwards'—some directions only use one form, but castlewards is so rare it barely matters anymore!
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