Richmond Castle, Richmond, North Yorkshire
Richmond castle was probably built in the 1070s by Alan Rufus to defend his estates against Anglo-Saxon nobles who had lost their land and power. It was an enclosure castle. It was originally triangular in shape with a massive stone wall on two sides. The third side was protected by the drop to the River Swale and possibly a timber palisade. The eastern wall was covered by three projecting towers. Dominating the castle is the square keep. It was 30.6 metres high and built in the second half of the 12th century. The nineteenth century detention block held conscientious objectors during World War I. The prisoners recorded their personal and political beliefs in the form of graffiti. More graffiti was added during the Second World War when the cells were used as a punishment block for disorderly behaviour by soliders. This site is now in the care of English Heritage (2012).