The Giant's Ring is a henge monument at Ballynahatty, near Shaw's Bridge, Belfast. It dates from the Neolithic period and was built around 2700 BCE. It is near the Shaw's Bridge crossing of the River Lagan, a point which has been used as a crossing of the river since at least the Stone Age. The original purpose of the monument was most likely as a meeting place or as a memorial to the dead.
The site consists of a circular enclosure, 180 m in diameter and 2.8 hectares in area, surrounded by a circular earthwork bank 3.5m high. At least three of the five irregularly spaced gaps in the bank are intentional and possibly original. East of the centre of the enclosure is a small passage tomb with a vestigial passage facing west. There were reports of other tombs outside the enclosure, but there is no trace of these.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.