Milwaukee was built on beer, with credit due to beer barons such as Capt. Frederick Pabst, a German immigrant who founded the Pabst Brewing Co.

One of Pabst's lesser-known projects -- but one that evolved from an equal dose of passion -- is an 18,000-square-foot estate in Oconomowoc, WI, which he commissioned for his great-granddaughter, Elsa Pabst Byrnes, in the 1960s.

Every detail is lavish in this elegant Georgian Colonial mansion set on 14 acres in an affluent community west of downtown Milwaukee. Among its perks is the country's first Corian sink. "Evidently, the DuPonts were friends with the Pabsts," says listing agent Pat Bolger.

Spread over four levels, with 39 rooms total, the home also features the state's first elevator. You'll also find servants' quarters, a drawing room/library, a boat launch, an eight-car garage, 11 fireplaces, three kitchens, and a guesthouse.

"The home was built for elaborate parties. Elsa was quite the socialite," says Bolger, adding that the parties often extended into the next day, in part because the home's eight bedrooms and nine bathrooms could comfortably sleep 50 people. Plus, the 2,500-square-foot guesthouse has two bedrooms and two bathrooms.

In her 30s when she moved into the house, Byrnes raised her children there until selling it in 2001. She now lives in Arizona.

The home is on the market again, for $4.2 million. The current owner is also a socialite, who hosted about 10 charity events in the home per year. She's selling to be closer to her adult children.

The owner "had a wall knocked out in the living room to accommodate her large dining room table, and she built a kitchen suitable for caterers," says Bolger. But the crown jewel is a retro-themed ice-cream parlor -- right down to the black-and-white floor tiles -- that the owner built for her kids, who adored ice cream.

Another modification she made was the addition of a terrace overlooking the lake. She'd spotted one on a lakefront mansion while vacationing in Europe and fell in love with the romantic touch. This new alfresco space also adds to the Old World feel when gazing out at the 200 feet of lake frontage. "You feel like you're not even in Wisconsin… You're in the Mediterranean," says Bolger.

Finding the right buyer may take time -- or will it? In recent years, Bolger's noticed an uptick in sales of lakefront estates in lake communities west of Milwaukee. In 2009, a 12,000-square-foot, 100-year-old property in Chenequa sold for $5.8 million.

What hasn't changed is that these properties are often snapped up by buyers from other locales who want a second home. Within the past year, Bolger has sold lakefront homes to residents of other states, including a Brookfield, WI, native who, as a young boy, dreamed of living on the lake.

"There are not many homes of this caliber. There's just a handful each year that sell in the $2 or $3 million range," says Bolger. "It's like selling an expensive car. Very few people can afford it." Many of these properties are summer homes for wealthy Midwesterners who spend winters in Arizona or Florida.

"They're not going to be here in the dead of winter," says Bolger.