Updated:June 5, 2023

Remains of the Imperial Japanese Army Sasebo Fortress Marude-Yama Battery Observatory

 

 

This facility was built to control the shooting of 28cm howitzers equipped in Marude-yama battery by informing the battery of the distance to enemy vessels and impact points measured with a range finder. Basically, the exact location could be measured by forming a right angled triangle with a base line connecting the altitude of the observatory and the sea level. (perpendicular base line method) Trenches were dug around the facility so that observing soldiers could not be seen from the sea. This observation has an armored overhead cover which can be seen only here and at the 1^st Tomoga-shima battery in Yura Fortress (Wakayama city, Wakayama prefecture)