Coastal fortress - Kaiganyousai

… A fortress is a permanent position seen before World War I, a strongly defended independent defensive area. It is divided into land fortresses and coastal fortresses according to its location, large fortresses and small fortresses according to its size, and permanent fortresses and temporary fortresses according to the period of construction. Large land fortresses were built at the most important strategic points, and usually contained military buildings and resource-rich residential areas within. They generally consisted of various defensive lines, such as forward positions, a main defense line, an inner defense line, an enclosure, and multiple enclosures. …

*Some of the terminology used to refer to "coastal fortresses" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…　要塞は第1次大戦前にみられた永久陣地であり，強固に守備した独立防御地域をいう。所在地により陸地要塞と海岸要塞，規模の大小により大要塞と小要塞，構築の期間により永久要塞と臨時要塞に分けられる。陸地大要塞は，最も重要な戦略要点に建設されたもので，その内部に軍用建築物や資源豊富な住民地を包含するのを通常とし，一般に，前進陣地，本防御線，内部防護線，囲郭，複郭などの諸防御線からなっている。…

※「海岸要塞」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報