blockhouse
/ˈblɒkhaʊs/noun
1- a reinforced concrete shelter used as an observation point（用作观察哨的）混凝土掩体。
1.1
- historical a one-storeyed timber building with loopholes, used as a fort〈史〉（旧时开有枪眼的）木堡。
1.2
- US a house made of squared logs〈美〉（用方木建造的）木屋。