Renhold Castle also known as Howbury, earthwork at Water End Farm, was a Medieval castle located in the village of Renhold, in the hundred of Barford, in the county of Bedfordshire, England. Renhold Castle was a timber motte-and-bailey castle, encased by a moat. It was located 4 miles east of Bedford Castle and a mile south of Great Barford Castle. Only earthworks remain at the site, which is a Scheduled Monument protected by law.