To be privately owned
Tattershall Castle

Tattershall Castle, a structure distinguished by its unusual brick construction, rises approximately 10 meters above sea level in the county of Lincolnshire, England. It is considered one of the most significant surviving brick buildings of the 15th century in England.
History+
The origins of Tattershall Castle date back to 1231, when Robert de Tattershall had a stone castle or fortified manor house built. Between 1430 and 1450, a reconstruction and expansion was undertaken by Ralph, the 3rd Lord Cromwell and Treasurer of England. Although ample stone was available in the region, Cromwell opted for brick as a building material, a fashionable choice at the time, introduced by Flemish weavers. Approximately 700,000 bricks were used for the construction, earning the edifice the reputation of "the finest piece of medieval brick-work in England." After Cromwell's death in 1456, the castle initially passed to his niece, Joan Bouchier, but was confiscated by the Crown after her husband's demise. Sir Henry Sidney acquired the castle in 1560 and sold it to Lord Clinton, later Earl of Lincoln, in whose family it remained until 1693. Thereafter, the castle gradually fell into disrepair.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: Colin Jackson
This description draws on the facts documented in the linked Wikipedia article; Wikipedia content is licensed under CC BY-SA 4.0. Wording and editing: Mobile History.
Location: 53.1014, -0.1934