虎穴龙潭
      Explanation: Long home to deep puddles potential tiger hiding in the lair. Analogy very sinister place.
      Usage: Joint type; as object, attribute; metaphor very dangerous place
      Source: Ming Xu Zhonglin "Gods" 70 back: "withstood Kongxuan knife. II will be another war in the Longtan ventured into."
      Examples: Hero does not avoid danger thanks seat, to ~, force to save remaining years. (Ming Shinai "Tales of" forty-back)
  • Thesaurus:  dangerous spot as a dragon's pool and tiger's den— — a danger spot, Tiger Cave vauclusian spring