The Wikipedia article of the day for June 20, 2017 is Melbourne Castle.
Melbourne Castle was an incomplete medieval castle, founded in 1311 by Thomas, 2nd Earl of Lancaster, in Melbourne, Derbyshire. It was built on the site of an earlier royal manor house that had provided accommodation for noblemen hunting in a nearby royal park in the reign of King John. After the earl’s execution in 1322 for opposing Edward II, the castle was mainly in the possession of the Crown or the Earls and Dukes of Lancaster. Improvements and repairs were made by John of Gaunt and others, and the building was in generally good condition throughout the fifteenth and early sixteenth centuries. John I, Duke of Bourbon, was kept at Melbourne for 19 years after his capture at the Battle of Agincourt in 1415, and it was considered as a possible prison for Mary Queen of Scots. The castle was in decline by the end of the reign of Elizabeth I. It was purchased in 1604 by Henry Hastings, 5th Earl of Huntingdon, who had his own castle in nearby Ashby-de-la-Zouch, and was gradually demolished for its building materials. All that remains is a short section of wall and some foundations. The ruins are grade II listed and the site is a scheduled monument, with no public access.