There are only a handful of original Japanese castles still standing and although this example is relatively small, Marugame displays traditional Japanese construction of the period. The stone mason, responsible for building the foundation walls, was very highly skilled and known for building walls so steep and smooth, they were nearly unscaleable. However, he informed the Lord that given pieces of iron, to form hand worn "claws", he could easily climb any wall. Climbing claws were fashioned and the mason easily scaled the castle walls. Fearing that this skill might leak out to his enemies, the Lord asked the mason to inspect construction at the bottom of a 65' deep well, then had stones dropped, killing the mason. Sometimes its not wise to brag about ones abilities😢