駐屯

1. Origins, structure, and basic meaning

• Structure: 駐屯 (ちゅうとん) means stationing military units in an area. 駐屯していた is a continuing state; nominal 駐屯を示す is a fact evidenced by records.
• Basic usage: Troops remain near a border in a story; records at castle ruins indicate a past military presence.

2. Common pitfalls and similar expressions

• Troops stationed on site and stationing known from records
  • The station location takes に. The second example does not assert a current garrison; it concerns documentary evidence of past presence.