Boppard’s most famous sight is a castrum, a Roman Fort. The military camp of Bodobrica was established here in 360 AD. It is thought to be the best preserved example north of the Alps today. It once had 28 towers, and was a commercial centre as well as a fort. It was 308 × 154 metres and formed a rectangle of 4,7 hectare. The walls were 3 metres thick to the land side and 2,5 metres thick to the Rhine side. With a height of 9 metres and 20 horse-shoe shaped towers to the land side, each 27 metres apart, the wall made a very powerful fortification.
The fort can be wandered around freely and it is in remarkably preserved condition. Many of the finds that have been recovered and excavated from the site can be found in the Boppard museum.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.