Tattershall Castle was originally a 13th century stone enclosure fortress, founded by Robert de Tatershall. Of this earlier castle, only parts of the curtain wall, flanked by the bases of three cylindrical towers remain above the moat. In 1434, Ralph, first Lord Cromwell, added a remarkable rectangular brick great tower, which dominates the inner ward. Of five storeys, with octagonal corner turrets, the basement is below ground level and two of the upper storeys have magnificent heraldic fireplaces. The concentric outer bailey is divided into two wards by a wide moat and the ruins of a brick built stable block stands in the outer ward. In the middle ward, stands a brick two-storey range is known as the guardhouse, sadly of the other various buildings and gatehouses, there are only foundations. 11 miles north-east is Bolingbroke Castle.