Fortification
01
要塞, 防衛構造
a defensive structure or system constructed to protect an area or position from enemy attacks, typically including walls, towers, and other defensive elements
02
強化, 要塞化
the addition of an ingredient for the purpose of enrichment (as the addition of alcohol to wine or the addition of vitamins to food)
03
要塞化
the art or science of strengthening defenses



























