The Nio-mon gate was designated as a new national treasure in 1954, after it had been repaired, because only a few Nio-mon gates were built in the early Kamakura period.
鎌倉時代初期築の二王（仁王）門は極めて稀少で、修理完工後の昭和29年（1954年）には新国宝に指定された。