through holes and stone dropping windows in these towers.

"Meanwhile, Kumamoto castle's walls are nicknamed nezumi-ishi (mouse walls) as they were deemed impossible for even a mouse to scale," says Mitchelhill.

"Unfortunately, the 2016 earthquake destabilized many of the walls and buildings at Kumamoto castle. They are expected to take many years to repair."

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Of all castles you've visited, which one is the most beautiful?

Built in 1603, Nijo Castles was the residence of the Edo era's first shogun David Green

"The palace at Nijo castle, in Kyoto, is extremely beautiful. It is the oldest surviving castle palace at over 400 years old," says Mitchelhill.

"Built by Tokugawa Ieyasu (founder and shogun of the Tokugawa shogunate) in the Edo era 1600-1868, Ieyasu employed the most skilled artisansof the day to decorate the palace walls and screens with exquisite paintings and carvings.

"Through this opulence, Ieyasu was able to impress his power upon visitors to the palace."

Did you encounter any surprising stories along the way?

"Maruoka castle has a 'human post' (called a hitobashira) entombed in its stone base.

"During the castle's construction in 1576 there were problems stabilizing the stonewalls. It was decided that a human sacrifice was needed to appease the gods," says Mitchelhill.

"A blind peasant woman called Oshizu volunteered to be a hitobashira in exchange for her son to be taken in by the lord of the castle and made a samurai.

"Unfortunately, the lord was unable to fulfill his promise as he was transferred to another castle soon after.

"Whenever the moat floods, as it often