【Designated by the City：Tangible Folk】Katsu

It is located inside Katabaruinau (an inland sea reef), which is about 200 m away from reclaimed land for a Shimojijima Airport runway, to the west of the shore of Sawada. The present Katsu is said to have been made by Matsu Yoshihira in around 1850.
Fishing there skillfully utilizes the shelving shallow beach of Sawada; People surround the area with stones so that fish come in at high tide, and get caught in a net at the exit which is left open while other exits are closed at ebb tide.The structure is made of stones piled up in a radial manner from north to south, with an exit at the apex. There remains stonework for about 300 m on the east side and 60 m on the west side.
The stonework is about 50 cm to one meter high depending on the configuration of the sea floor. The total area is about three hectares. The stone wall is a solid dual-structure. The exit waterway is 50 cm wide and three meters long.