The Hara Castle Ruins, as featured in the television program Japan's Strongest Castle, are situated in a spectacular natural setting, with breathtaking vistas from the main defensive enclosure, endless blue skies above, stunning views across the water to distant Amakusa in Kumamoto Prefecture, and in the background the magnificent Mt. Heisei Shinzan.
This aerial photo show the site from a different angle.
Hara Castle Ruins
Here's a question.
From this photograph, it looks like the people inside Hara Castle had no way to escape, trapped between the ocean on one side and the shogunate forces of 120,000 troops stationed on land.
So if the rebels were effectively confined inside, why is Hara Castle considered one of Japan's strongest castles?
The sea was their escape route
From surviving drawings of Hara Castle, we know that it had a number of gates with names such as Otemon, Tajirimon, Renchimon and Oemon that led directly out to sea. It was truly a "castle of the ocean," making full use of the Ariake Sea. The ocean waters near the castle had complex tidal currents that made it too hard for the shogunate forces' ships to position themselves offshore. However the rebels, who understood the currents well, could easily slip through the dragnet and make their way out to the sea.
It is thought that access to food and other supplies brought in by boat is what enabled the estimated 20,000 or so rebels holed up inside the castle to survive for nearly three months, despite the shogunate forces' attempts to starve them into submission. The rebels who entrenched in Hara Castle were not completely trapped.
According to Hideo Hattori, a member of the Special Committee for Hara and Hinoe Castle Ruins, Amakusa Shiro (the leader of the Shimabara-Amakusa Rebellion) and his followers called for a massed insurrection by Christians throughout the country, and were also hoping for reinforcements to be sent from the Portuguese stationed in nearby Macau.
The location of Hara Castle on coastline of the Ariake Sea would have been ideal for the Portuguese fleet, with ready access to the rest of Japan and indeed the rest of the world. This was part of the grand vision of the rebels, who were confident of their prospects for victory.
But the massed uprising of Christians living in other parts of Japan that they had hoped for did not eventuate, and Portugal, which was starting to see its naval supremacy in East Asia usurped by Holland, failed to send reinforcements.
The battle ended ignominiously: Hara Castle was eventually taken and there were few survivors among the 20,000 revels (opinion is divided about the number of rebels).
What if the nationwide uprising had happened after all...?
What if Portugal had sent reinforcements?
The history of Japan might have taken a very different course.
The Shimabara-Amakusa Rebellion represents a fascinating historical battle that could have had any number of outcomes."