According to legend these holes were made to support standards displayed during an 11th century battle between Scots and Danes. Seems a lot of effort just to stop a couple of flags falling over for a battle that most likely never happened. But what other reasonable explanation is there? I’m sorry there is no scale in the photos. However, the holes are 13” apart, the larger one is roughly 20” x 12” x 11”, while the other is about 14” x 11” x 10”.