#citadel__bastion  a stronghold into which people could go for shelter during a battle
  supertype:  stronghold__fastness  a strongly fortified defensive structure
  subtype:  acropolis__acropoli  the citadel in ancient Greek towns
  subtype:  kremlin  citadel of a Russian town
  subtype:  Kremlin  citadel of Moscow, housing the offices of the Russian government

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