Here we are, in a darkened dungeon deep underground, watching as our tour guide shines a flashlight on various torture devices and explains how they were used to spike, stretch, suffocate and inflict pain on sufferers in the Middle Ages. Not your typical Napa Valley winery tour, I’ll say.

Then again there is nothing typical or ho-hum about Castello di Amorosa, a spectacular $40 million Calistoga winery built in the style of a medieval Tuscan castle. Besides the dungeon it has 106 other rooms, a chapel, church, farmhouse, dry moat, drawbridge, hidden passageways, courtyards, massive stone walls and towers that rise in the center of picturesque hills and acres of grapevines.

It is not mandatory to take a tour of the castle when you go, if you go, although there are so many wonders and curiosities about the place you really don’t want to miss any of them. We are there as part of the Napa Valley Wine Train’s “Castle Winery Tour,” and our guide greets us in the chapel with an introduction you don’t hear every day.

“Hi,” he says. “I’m Mark. I’ll be your tour guide and bartender.”

The bartending would take place later, at the end of the tour, in a private tasting room. As Mark explains, Castello di Amorosa makes lots of wine in addition to hosting tourists from Italy to Indiana. (Word to the wise: The castle can be shoulder to shoulder with people on busy weekends. Best to go midweek if you can.)

Seated in the chapel listening to his introduction, we have a chance to admire a lovely fresco depicting Mary and Joseph set back into the sanctuary behind an arch. Perhaps surprisingly, given the castle’s Imax-sized scale and scope, attention and care are given to the details. Outside the chapel, tucked into a recess in a stone wall—8,000 tons of imported stone and a million bricks went into the making of the castle—is a figurine of St. Catherine of Siena, holding flowers and a Bible.

The owner and chief visionary of Castello di Amorosa (translated: Castle of Love) is Dario Sattui, whose dream it was to create a working tribute to Italy’s distant past and his family’s winemaking heritage. (His great grandfather Vittorio Sattui founded St. Helena’s V. Sattui Winery, which Dario also owns.) All around us, as we stand in the central courtyard, we can see sincere efforts at historical authenticity blended with fantastic flights of the imagination. Perched on a wall not far from the chapel is an iron device that medieval kings and nobles used to display the decapitated heads of their enemies. Beyond that is the wrecked remains of a tower, built and left deliberately in this state to simulate an enemy attack on the castle, conducted perhaps by the friends of those guys who had their heads chopped off.

Some years ago Pixar and Disney studios held a private employee screening of the animated movie “Brave” at the castle. It may be the film’s creative team also conducted some research there because the Great Hall is patterned after a royal banquet hall in which you can easily visualize the lords and ladies of “Brave”—its setting is feudal Scotland—feasting on black pudding and mugs of mead on the long wooden dining table in the center of the room.

Italian-born artist Fabio Sanzogni painted the frescoes in the Great Hall and everywhere else in the castle, including the chapel and yes, even the restrooms. There are two knights in armor on a men’s room stall and a smile-producing painting of a man in a hat from the Middle Ages at the entrance.

Given that the castle opened in 2007—it took 15 years to build—all this antiquity is still only a decade old, including when you go down below ground and explore the cool, sweet-smelling wine caves. (In a nice bit of symmetry the castle goes four stories below the ground and at its highest point four stories above it.) Like a pied piper of tour guides, Mark leads us along corridors lined with wine barrels, walks us through a barrel tasting of a young Cabernet Sauvignon, shows us the iron-gated cells in the dungeon—used for aging bottles of wine—and then delivers us to the torture chamber with all those fascinating ways to inflict pain on people, including a chair with spikes on it where you sit.

The torture chamber is not the climax of the tour, though. That comes in the tasting room where our guide, slipping into his bartender’s role, fixes us up with swallows of Pinot Bianco, Sangiovese, Il Barone Reserve and other award-winners in the castle’s lineup.

Good wine, it is said, tells a story of place and time—the place where the grapes were grown and the wine created, and the time in which it occurred. Castello di Amorosa tells a story too—a fantasy adventure of lords and ladies, heroic battles and dreams realized. My advice: Share the fantasy.