There is a really good winery in Napa Valley, called Castello di Amorosa. Really good wine, and it is also built as a medieval castle. I bet there are more places like that around the world.
Towers, parapets, (non-working) drawbridge (weighing tons, and already on its second timbering). Murder slits and a secret staircase...
Fully modern wiring, plumbing, and inner structure (faux stone facade). But a "medieval castle".