鐵甕城 [铁瓮－]

Jyutping tit3 ung3 sing4
Pinyin tiě wèng chéng

Definitions (Wiktionary)
  1. name
    Tie Wengcheng (sub-city of Zhenjiang built by Wu Sunquan during the Three Kingdoms period)
    (syn.) 甕城, 瓮城