The "Gusuku Sites and Related Properties of the Kingdom of Ryukyu" are representative stone works of Okinawa. These diverse structures include castle ramparts, cobblestone roads, graves, garden ponds and bridges. The architecture of Okinawa can be characterized with the context of a "stone culture." Common to each of the Gusuku is the use of stone as an important building material, a characteristic that can be seen even today in the evidence of construction. Among these, the stone masonry of the remaining portions of castle ramparts trace the changes in characteristics of masonry processing and techniques.

Stone masonry techniques are roughly divided into those that utilize the existing shape of the rock with no processing and those that utilize cutting methods to shape the rock. A comparison of both these techniques shows the piled masonry style to be the more ancient technique. Cut masonry techniques are further divided into coursed "Nunodzumi" and fitted "Aokatadzumi" masonry techniques. Within the history of stone masonry there is recognition that its technical evolution goes from coursed or regularly cut stone to the fitted masonry that adapts the natural shape of the stone.

"Nodzuradzumi" Rough Faced Masonry
The primary characteristic of rough-faced piling technique is, as its name denotes, the use of stone just as it is, without processing. There is almost no uniformity of the stones. There are many walls where the stones are predominantly round and those that are made of flat and thin stones.
Representative of the reinforced and perfected rough-faced style is the masonry of the ruins of Nakijin Castle.
Gusuku Sites with Ramparts Utilizing Rough-faced Masonry:
The ruins of Nakijin, Nakagusuku, and Zakimi castles