茨城県[ibarakiken] Ibaraki prefecture (Kantou area)
王城[oujou] royal castle
下城[gejou] withdrawing from the castle
牙城[gajou] stronghold (esp. of an enemy or opponent)
開城[kaijou] capitulation (of fort)

宮城[kyuujou] Imperial Palace
宮城県[miyagiken] Miyagi prefecture (Tohoku area)
傾城[keisei] beauty
堅城[kenjou] strong fortress
古城[kojou] old castle

胃壁[iheki] stomach lining
外壁[gaiheki] outer wall
隔壁[kakuheki] barrier wall
岸壁[ganpeki] wharf
胸壁[kyouheki] chest walls

合壁[gappeki] neighbor with just a wall between
磁壁[jiheki] magnetic domain
障壁[shouheki] enclosing wall
城壁[jouheki] rampart
絶壁[zeppeki] precipice