The unique Kochi castle, "anti-ninja" Shinobi-gaeshi

Amongst all the Japanese castles, only 12 remained until today with the original main tower, with original defensive elements like ishi-otoshi (hidden openings used to throw stones against the attackers).

And amongst the 12 original castles, the castle from Kochi stands out with its unique defensive system: a row of katana-like sharp blades surrounds the castle's walls. Called shinobi-gaeshi, they were designed to prevent the ninja (shinobi) attackers to escalate the walls...