Sixagenta Prista Castle is an ancient Roman fortress located on a hill near the Danube River in the northwestern part of the city of Ruse. There is a Thracian village here, and in 2006, archaeologists found the remains of a Roman military ship, hence the castle's name. Sixagenta Prista means "the harbor of the sixty ships." Nowadays, the castle serves as an open gallery for the Regional History Museum of Ruse.