Shirabe
要塞化
English jmdict
1
noun (common) (futsuumeishi) fort;stronghold;fortification
そこでまだ要塞都市の遺跡をみることができる。
You can still see the remains of the fortress there.

要塞化ようさいか

Noun Irregular
English jmdict
1
noun (common) (futsuumeishi)noun or participle which takes the aux. verb suru fortifying;fortification