Lochranza Castle, Isle of Arran

A tall, twin-towered medieval hall-house standing on a shingle spit that curls into Lochranza bay at the northern tip of Arran, ringed by steep hills. It's a lovely subject because the water wraps almost all the way round the castle at high tide, so an orbit gives you the ruin mirrored in the sea loch with the mountains of the north Arran ridge as a backdrop. A climb-out to the south reveals Glen Chalmadale and the serrated skyline of Caisteal Abhail; face north and you look out to the Kintyre peninsula across the Kilbrannan Sound. Golden-hour light on the sandstone is the pick. The castle is in Historic Environment Scotland's care but is an unstaffed, open-access ruin — HES asks that you don't take off or land from within a monument in its care, so launch instead from the adjacent open shingle/grass foreshore under Scotland's access rights and keep the machine outside the monument footprint. Red deer wander into the village and often onto the flats around the castle, so you may get a bonus subject — don't harass them. Arran sits well clear of any FRZ (Prestwick is ~35km east across the firth). Coastal breeze funnels down the glen.