It can be said that the basic purpose of the nawabari is to effectively arrange three major kuruwas, or the honmaru (the core of the castle), and the ninomaru (literally "Second circle") and sannomaru (literally "Third circle"), both of which serve as auxiliary areas for the honmaru, so that the honmaru is surrounded by the ninomaru and sannomaru.
縄張の基本は主要な3つの曲輪、すなわち城郭の核となる本丸（ほんまる）の周囲に、補佐的な二の丸（にのまる）、三の丸（さんのまる）を効果的に縦深配置することと言える。