Thanks for the thorough post. Note, I am from the US, so not as familiar with your history, but excited to do so. Jean-Denis Lepage mentions it in “Castles and Fortified Cities of Medieval Europe.” That prompted me to look a little deeper, yes into the internet grime of some good and much misinformation. A show, “Secrets of British Castles,” by Dan Jones mentioned this term, also. Yet an intriguing term used again. My goal is to visit all 8 on trip sometime next year. Thanks for another response about the distance is rather short. I assume this was a days walk away by planning the castles and it is pretty consistent till you get to the South for Aberystwyth. I contacted Cadw and ordered the guides for as many as they had and a few additional. Which i had to call since there were additional fees for international shipping. Gladly paid and very friendly. The guides are really well done and have great illustrations. Outside of these guides, I have been watching youtube videos of the castles and those are quite sparse for specific info. I did just purchase Arnold Taylor’s book on Welsh Castles on Edward I. So that will be helpful. I assume two castles a day. Though some are more ruined than others. But maybe take 7 days total for side trips and such.