The Great dolmen of Dwasieden was excavated in 1970 by Ewald Schuldt. The megalithic site of the Funnelbeaker culture was constructed between 3500 and 2800 B.C. Of the 54 kerb stones - including the four guardian stones - 41 have survived. The rectangular, roughly east-west oriented chamber at the wide end of the frame, with its western entrance and porch consists of seven supporting stones, a half stone the height of the uprights and five slabs, on which there are three large (on the chamber) and three small capstones. Only the central capstone of the chamber is missing. One of the four guardian stones at the southwest end, which had already been overturned in the past, has 40 cup marks, one of the kerb stones has three more. The site is a prime example of the porch dolmen, typical of this region. A two-metre-long porch runs past the support-high half stone to the 4.0 metre long, 1.7 metre wide and 1.4 metre high chamber. The hall consists of red sandstone slabs, annealed flint and a clay floor.References:
Goryōkaku (五稜郭) (literally, 'five-point fort') is a star fort in the Japanese city of Hakodate on the island of Hokkaido. The fortress was completed in 1866. It was the main fortress of the short-lived Republic of Ezo.
Goryōkaku was designed in 1855 by Takeda Ayasaburō and Jules Brunet. Their plans was based on the work of the French architect Vauban. The fortress was completed in 1866, two years before the collapse of the Tokugawa Shogunate. It is shaped like a five-pointed star. This allowed for greater numbers of gun emplacements on its walls than a traditional Japanese fortress, and reduced the number of blind spots where a cannon could not fire.
The fort was built by the Tokugawa shogunate to protect the Tsugaru Strait against a possible invasion by the Meiji government.
Goryōkaku is famous as the site of the last battle of the Boshin War.