Known as Bannon Island in honor of the Irish carpenter who first built a home there, the property has never before been listed for sale.
An extraordinary private island in Florida that was settled by an Irish carpenter in the 1880s—and has remained in the hands of his family ever since—has hit the market for the very first time.
Located on Lake Marion near Haines City, the 23.32-acre parcel, which is known as Bannon Island in honor of the man who first built a home upon it, sits directly between Orlando and Tampa, and is only accessible by boat, helicopter, or seaplane.
However, it is the location of the island that is especially rare, according to listing agent Lisa Kleine of Red Bird Realty, who has brought the property to the market for $12 million, marking the first time in around 150 years it has been made available to buyers.
“Saltwater islands are common as you get down to the Keys, but to have one in the interior of Florida, specifically in between Orlando and Tampa, makes it a great location for somebody who craves privacy but at the same time wants to be in the middle of it all,” Kleine explains.
“I love the feeling of stepping back in time, but still having all the luxury accommodations needed to enjoy life today.”
The island is in an inland lake and is almost 24 acres. (BlueBird Property Media) 
The original home is in the shape of a Celtic cross. (BlueBird Property Media) That luxury comes in the form of a sprawling main house on the island, which was built by its original settler, Patrick Bannon, a carpenter who came across the parcel in the 1880s, when it was occupied by Native Americans.
Bannon, who moved to Florida from New York City, where he had carried out work on one of the mansions commissioned by the Vanderbilt family, according to Mansion Global, became friends with the people living on the land and they ended up gifting it to him.
The carpenter then set about turning the island into a private retreat, beginning with an eight-sided structure built in the shape of a Celtic cross, which used reclaimed cyprus for its walls.
That two-story original home has stood since then, surviving many perils, including Hurricane Charley which went right over the area in 2004. Shortly after, the family decided it needed more room, adding a large addition.
Over the years, the island has passed through several generations of the Bannon family, most recently falling into the hands of his grandson, Patrick O'Leary, 84.
“This man built this historic home with his own hands and then four generations later, we're experiencing the renovation that his grandson catapulted off of his original design with his new expansion that mirrors the original historic house,” Kleine explains.
Today, there are a total of three bedrooms and four bathrooms in the main house, with more places that could be sleeping areas.
“[The family] used an architect who was famous through Southern Living magazine to do the rendering. It is luxurious and timeless and state-of-the-art in in its whole expression of honoring what was in old Florida but what is the new Florida,” she adds.
The original home has walls of reclaimed cypress wood. (BlueBird Property Media) 
The L'Orangerie has walls of glass and a showpiece chandelier. (BlueBird Property Media) 
The library is suspended with cables and has a glass floor. (BlueBird Property Media) 
The kitchen is in the new addition. (BlueBird Property Media) While the historic part features wood the new space features glass.
“You have a L'Orangerie [with] giant glass walls so that you can experience the Florida sunlight and the big lake views and all the natural wildlife that inhabits the island," Kleine points out.
Highlights are the suspended library and a muti-story glass chandelier made from a hundred blown-glass drops.
“The chandelier mimics a rainstorm and was commissioned by the owners,” Kleine explains. “They even thought to put in split air conditioning units to move the glass so that it's always in motion, like a rainstorm would be. It's glorious to look at.”
The 5,034-square-foot main residence is now a combination of old and new, connected by a glass walkway.
“It's two in one,” Kleine says. “You can literally walk on one side of the house and experience old Florida and the reclaimed cypress wood and be surrounded by those luxurious walls, and then you move to the other side of the house and you're in the kitchen that can serve two people or 40 people.”
An additional 2,698-square-foot duplex the owners call the Dog Trot is nearby with two identical units, each featuring two bedrooms and two bathrooms. It was where the sellers lived when they were adding on to the main house.
It also has its own history.
The new addition mimics the historic portion. (BlueBird Property Media) 
A duplex is also on the property. (BlueBird Property Media) “That's where the original Native Americans had their homestead so that they could experience the breeze from the lake and also be sheltered in the cooler months,” she explains.
Two other structures are on the island along with acres of fruit trees, mostly Valencia oranges but also grapefruit, guava, and more. There also is abundant wildlife and native forest.
The island is only accessible via boat or seaplane and from there a car can get you almost anywhere, making the island attractive to multiple kinds of buyers.
“It could be for a conservationist who just wants to preserve a piece of old Florida. It could be for somebody who's seeking an incredible venue for weddings, special occasions, family reunions, or it could be for somebody who just wants complete privacy but wants access to Tampa and Orlando within 45 minutes,” Kleine says.
Kleine first saw the property more than 20 years ago while attending a party on the island.
“I felt like I stepped into another world. I felt like I was a time traveler. I didn't know really what to think completely at first because there was so much to take in.”
That meeting eventually led to Kleine listing the legacy property decades later when the family decided to sell.
“It's an opportunity of a lifetime that I don't take lightly. I'm very humbled by it,” she says. “I believe I met this family for many reasons, but one of them was to eventually help them and partner with them in transferring this exceptional property that was pioneered by their by their grandfather into hands that will love it just the same.”