The Second Compound housed the living quarters of the palace grounds.

The modern day Nakagusuku is one that has been altered and strengthened by Gosamaru himself. The history of this can be seen in the walls. Let’s take a closer look at the mason work of the castle walls. Depending on the era of history, the style of masonry changes, and they can be divided into three major categories: “nomen” masonry, “tofu” masonry, and “kikkō-midare” masonry.

First, the nomen masonry style. This is an old style of masonry that takes stones and stacks them together as they are naturally. Tofu masonry on the other hand is a more advanced style which takes stones that have been shaped into block shapes and stacks them together. These two styles existed in the castle structure before Gosamaru came around.

Gosamaru went on to create an unprecedented style of masonry, kikko-midare. In this complicated style, the stones are shaped into a pentagonal shape and puzzle-pieced into each other. Out of the three styles, this is the most durable method as well as the pinnacle of masonry technique at the time.

The third and fourth compounds were both additions that Gosamaru oversaw so all of the structures are built in the “kikko-midare” style. The first and second compounds both have parts rebuilt in this style as well.

The reason for this development in masonry is due to the island’s large supply of readily available limestone. This island was created as a result of coral reefs coming together into a mound of land and rising out of the sea. Since limestone is less like a mineral and more like a living organism, it’s actually quite soft which can be attested to by the seashells which have been preserved in the structure throughout.