Threave Castle in Dumfries and Galloway

You're standing at Threave Castle, on a flat island in the River Dee, about two and a half kilometres west of the town of Castle Douglas. Start with that tall, rectangular tower. It's over twenty metres high and was built in the 1370s by Archibald Douglas. The English called him Archibald the Grim, for the grim way he fought. It was one of the very first tower houses in Scotland.