Facing the cathedral across Exchequer Gate, this castle was built by William the Conqueror in 1068, incorporating the remains of Roman walls. The castle was used as a debtor's prison from 1787 to 1878. In the chapel you can see cagelike stalls where convicts heard sermons; they were designed this way so inmates couldn't tell who their fellow prisoners were, thus supposedly preserving a modicum of dignity. The castle's star exhibit is an original copy of Magna Carta, signed by King John in 1215. This is one of only four surviving copies of the original document, and one of few ever to have left the country—it was secretly moved to Fort Knox for safekeeping during World War II. A major renovation in 2015 opened up the wall walk for the first time, allowing visitors to make a complete circuit of the battlements (totaling more than ¼ of a mile). In addition, a 3D cinema shows a high-tech film about the history of Magna Carta.
Castle Hill, Lincoln, LN1 3AA, England