There's a mixed reaction when I announce I'm off to "the Castle". This is Napa, so "which wineries are you doing?" is the standard opening question when you meet a local. They each have their own must-tries but the Castle is often met with a slight smirk or an ever-so-subtle roll of the eye.
Some declare it a "tourist trap" and others claim that, contrary to popular belief, each brick was not imported from Europe, therefore making it a "gimmick".
Say what you will, but nothing can come between me and a castle doubling as winery, sitting picturesquely surrounded by 12.5ha of vines, red climbing-roses and white peacocks.
Set atop the hills of Calistoga, Castello di Amorosa (Castle of Love) was 15 years in the making for Italian owner Dario Sattui. His great-grandfather landed in San Francisco in 1882 and opened a bakery, but soon realised wine offered more money than pastries.
Sattui continued with family tradition and purchased the 69ha Calistoga property in 1993.
"He bought it with the vision of a small Tuscan village-style winery but got bored so decided to spend a little more and make it authentic," we're told.
A "little more" equated to around US$35 million ($41m) which was spent over 15 years, as nearly one million antique bricks were shipped from Europe to build the eight-storey, 107-room medieval wonderland.
For US$19, visitors can roam the upper levels and taste the Italian-style wines. But it's the tours below that are the real fun.
Wandering past dark dungeons and through tunnels guarded by iron gates and lined with barrels as far as my eye can see, I can't help feeling like I've stepped through Harry Potter's Platform 9¾ and into some secret booze halls at Hogwarts.
After a splash of pinot grigio at one of 15-plus tasting bars, we're escorted through the torture chamber, where a spike-covered inquisition chair sparks flashbacks to the bed of nails we would lie on at the school science fair. Something tells me this isn't so kid-friendly.
Despite being known for its Barone Reserve, the fruity, flowery La Fantasia wins me over. One sweet sip takes me back to Kiwi summers on the beach.
It's another taste of home we venture to next, heading down the road to Duckhorn Vineyards, to meet Wellington-born winemaker Bill Nancarrow.
Meet any Kiwi in Napa and they mention Nancarrow, who most play cricket or touch rugby with. "We had one rugby game and ended up with two broken collarbones so now we stick to touch."
Nancarrow interned at Duckhorn in 2001, a "three-month job interview" which led him to designing and building sister winery Paraduxx before returning to the mothership.
Dan and Margaret Duckhorn maxed out their credit cards buying the 4ha property in 1976. From their first vintage they became known for merlot and have since added 14 varieties, including a sauvignon blanc, which was the first wine Barack Obama sipped after becoming president.
Nancarrow insists we head up the hill to meet his Kiwi mate Jade Barrett, the winemaker at Ladera Vineyards. A Waiheke Island native, Barrett did his first harvest straight out of school and was instantly hooked. Having interned and worked in Napa, New Zealand and Australia, he landed back in California in 2004.
"I thought I'd end up going home but I slowly worked my way up and Napa's an awesome spot," he says, escorting us through caves lined with $1000 French Oak barrels. "To have your wines put out on national accounts and see them all around the country is very cool."
After a long day of wine-tasting we retreat back to The Westin Verasa to polish off the cab sav Barrett sends us home with then stumble down the road to grab dinner at famed burger joint Gott's Roadside.
Having rested our feet, we put them to work the next morning with a grape-stomping session at Grgich Hills. Squishing slimy fruit between my toes isn't as much outrageous fun as it looks on television, but it leaves me with a fun Instagram post and a grape-stained-footprint T-shirt.
The winery is celebrating the 90th birthday of Croatian founder Mike Grgich, a local legend who arrived in the US with "his signature beret, 10 books about wine and $32 then transformed the wine industry".
His 1973 Chateau Montelena chardonnay beat the best of France at the 1976 Judgement of Paris tasting and the following year he opened Grgich Hills.
Italian brothers John and Mario Trinchero are another famous Napa wine family, who bought Sutter Home with their life savings of US$12,000 in 1947.
Battling to make ends meet, it was 30 years before the business burgeoned thanks to Mario's son Bob experimenting with red zinfandel.
Spontaneously deciding to drain 20 per cent of the juice after grape-crushing (increasing the ratio of skins to give the wine more colour and body), he found himself with barrels of leftover juice which he fermented for fun, leading to the creation of white zinfandel.
Locals queued on the street to buy a bottle and by 1985 production had escalated to 850,000 cases a year, helping the Trincheros' business grow to become the second largest family-owned winery in the US.
Sutter Home also hosts a concert series, Live in the Vineyard, similar to NZ's summer Winery Tour, at which acts like James Blunt, the Backstreet Boys, Adam Lambert and Kiwi Natasha Bedingfield perform intimate sets at select vineyards as guests enjoy wine and food pairings.
This year's event next month features Colbie Caillat and Sarah McLachlan.
After a lunch of Maine diver scallops and fish'n'chips at riverfront restaurant Fish Story, we're ready for some bubbly at Mumm Napa.
Within minutes I'm regretting my decision to drive as six glasses of sparkling goodness are placed in front of me. Our host is full of fun facts and tips, like pouring demi-sec over fruit as a party trick and how tiny bubbles signal quality Champagne.
Opened in 1986 by French Champagne house Mumm, the local arm now outsells its French version in the US. As the official sparkling wine of the America's Cup, Kiwi Managing Director Simon Towns was thrilled to present Dean Barker with a jeroboam after Team NZ took out the Louis Vuitton series but sadly wasn't able to do the same for the final win.
Rather than relive America's Cup grief in nearby San Francisco we spend our free afternoon in Sonoma, a 30-minute drive from downtown Napa, through scenery reminiscent of New Zealand's lush greenery and rolling hills.
Perched on one of those hills sits Petroni Vineyards where former Stonyridge winemaker Martin Mackenzie is at the helm.
Mackenzie is a typical Kiwi bloke - easy-going, hardworking (80-hour weeks during harvest) and doing up shabby houses in his free time.
It's a contrast to his lavish workplace, a reminder that wine country, in many ways, remains a rich person's playground.
The stunning, luxurious home overlooking Sonoma sits vacant and the vine-bordered pool is untouched; its owner instead lives in the city.
Still under construction are caves which will house a chandelier-adorned dining room, tasting bar, events space and cheese storage.
The idea of having enough cheese to require its own room has my mouth watering so, after lunch at Californian-style French eatery Girl and the Fig, we head to the Epicurean Cheese Connection in Sonoma's cute Town Square to sample award-winning Sheana Davis' Creme de Fromage.
On our drive back to Napa, I take mental note that one day when I, too, own a winery in a castle, a storage room full of cheese is a must.
Westin Verasa Napa
Resting on the banks of the Napa River, the US$98 million Westin opened in 2008 and is home to Michelin-starred restaurant La Toque. With wooden floors resembling a wine barrel and a reception wall doubling as a wine rack, the lobby is a feast for the eyes. We have good intentions to explore our surrounds but surrender our evening to drinks at the lobby bar's poolside patio.
The Inn on First
For a cosier stay downtown, hosts Jim and Jamie - and their miniature schnauzers - will welcome you into their modern-day B&B, where phones are banned at breakfast and rooms are television-free, leaving guests to enjoy private whirlpool-tubs or wine on the patio. Culinary graduate Jim whips up intriguing dishes like omelette corn dogs for breakfast.
Meritage Resort and Spa
There aren't many spots where you find a cabana-lined pool, bordered by a tasting room in a cave, which sits under a slope of vines. The sprawling resort also boasts wine country's only spa in a cave, 12m underground. Don't leave without trying the Ahi Tuna Nachos at Crush Lounge.