Nakagusuku Castle stands on a hill with a fine view and an approximate elevation of 160m. The first enclosure overlooks the East China Sea in the west, and Nakagusuku Bay (Pacific Ocean), the Katsuren Peninsula, the Chinen Peninsula, and other surrounding islands including Kudaka Island in the east.
The location was perfect to keep an eye out for Chūzan at that time.

Nakagusuku Castle was built by the former Nakagusuku Aji before Gosamaru. The third and the north enclosures that still exist today were built as additions by Gosamaru who became Nakagusuku Aji in around 1440, and as with Zakimi Gusuku, you can find the advanced fortification techniques there.
It was his second time of fortification for Gosamaru and it can be noted that this was a more sophisticated gusuku in terms of functionality and defense.

In particular, you can see Gosamaru’s remarkable fortification techniques in the ramparts. He was confident of the quality of the “Aikata-zumi” masonry technique he had experimented on at Zakimi Gusuku, and he completed even more sophisticated, superb ramparts that incorporated the best technology of the time in terms of strength and defense. Therefore, the ramparts have never collapsed until today.

In addition to the masonry techniques, the arched gate at the rear gate is notable.
The beautifully curved gate stands there with dignity. Furthermore, it can be pointed out that Ufugaa (big well) as the water source is secured at the north enclosure.
Gosamaru’s high level of fortification techniques allowed him not only to secure the water source but also to prevent ground erosion by developing a drainage facility.

It is said that the first castle with full-scale stone masonry in Japan was Komakiyama Castle, built by Oda Nobunaga in 1563.
This reveals that Ryukyu had developed stone fortification techniques more than 120 years earlier than Japan, and thus proves Gosamaru as a genius of fortification who promoted these advanced techniques.