Drum is reckoned one of the three oldest tower houses in Scotland, its keep dating to around 1300. In the old walled garden the Trust has planted a Garden of Historic Roses, laid out in four sections by century so you can trace how roses changed down the years. Castle, garden and estate are open through the year, the castle to shorter seasonal hours, with an admission charge. It’s National Trust for Scotland; Portlethen station is about 13km east.