The Castle, Newcastle, or Newcastle Castle is a medieval fortification in Newcastle upon Tyne, England, built on the site of the fortress that gave the City of Newcastle its name. The most prominent remaining structures on the site are the Castle Keep (the castle's main fortified stone tower, pictured below right), and the Black Gate, its fortified gatehouse. The keep and Black Gate are now managed by the Old Newcastle Project under the Heart of the City Partnership as one combined visitor attraction, "Newcastle Castle".