The word 残垣断壁 is formed by combining two parallel descriptive phrases: 残垣, where the adjective 残 (meaning damaged or incomplete) modifies the noun 垣 (referring to a low wall or enclosure), and 断壁, where the adjective 断 (meaning broken or severed) modifies the noun 壁 (referring to a wall or barrier), with the entire compound directly conveying an image of ruined walls through this paired adjectival-noun structure.