A University College Dublin professor found that up to 80% of the medieval Roebuck Castle is still intact beneath Victorian plaster on the modern campus.
https://www.foxnews.com/travel/lost-medieval-castle-found-hiding-plain-sight-professor-spots-telltale-clues
https://www.foxnews.com/travel/lost-medieval-castle-found-hiding-plain-sight-professor-spots-telltale-clues