Tatsuoka Castle

Tatsuoka Castle - Credit: Wikimedia Commons

was a Bakumatsu period pentagonal "star fort" located in what is now part of the city of Saku, Nagano prefecture. It was the primary fortress of Tatsuoka Domain, ruled by the Ogyū-Matsudaira clan. Along with the Goryōkaku in Hakodate, Hokkaidō, it is one of only two star fortresses in Japan, and has been the castle ruins have been designated as a National Historic Site since 1934. Read more on Wikipedia

type: military installation
date from: 1867

Source: en.wikipedia.org