1A base — a facility or location serving as the operational headquarters for military activity, expeditions, or research; also used for infrastructure hubs (e.g. a cell tower 'base station').
沖縄には米軍の基地がいくつもある。
There are several U.S. military bases in Okinawa.
子供の頃、裏山に秘密基地を作って遊んだ。
When I was a kid, I built a secret base in the hills behind our house and played there.
日本の観測隊は南極に基地を持っている。
Japan's research team has a base in Antarctica.
このあたりは携帯電話の基地局が少なくて電波が弱い。
There are few cell towers around here, so the signal is weak.