Stan (Boulder Dude) and I drove out to Bishop Castle today. I think the closest thing (in spirit more so than in form) that I've seen to it is the House on the Rock. If you check out the difference in the places' respective websites, you'll get an idea of how different Bishop Castle is from a "tourist trap." Not that the pictures will really give you an idea of what the place "feels" like.
The rocks used in construction are uncut and come in all kinds of sizes and have been built over iron frameworks. Precarious-looking iron balconies and staircases are decorated with hand-wrought spirals and loops. The main rooms are open and drafty, and panes of glass have been shattered (my guess would be by storms, since the trees come up almost to the castle walls themselves) over the dirty, worn hardwood floors. It's the kind of castle that elves from The Lord of the Rings series would build, only heavier and rougher--fanciful and winningly lovely, but you wouldn't dream of trying to knock it over with anything less than a mountain, and you can see rust and repairs and wiring...
I have to say that Bishop Castle has become part of my idea of the "true" Colorado. Like barbecue in Memphis, or the big steps next to the lake by the Observatory in Chicago. The Cheyenne Mountain Zoo, the Stanley Hotel*, and this place.
*Which I haven't even seen yet, but there you go.
Stan's take on the castle.