An acre of paradise is for sale off the shore of the Florida Keys. 

Built by a New Jersey gastroenterologist, the private island address is looking for a loaded buyer in search of the very good life. The cost: $16.5 million.

When Klaus Meckeler — known in his industry for being one of the first US physicians to utilize specialized endoscopes in examining bile and pancreatic ducts — purchased the 1.37-acre spit of property in the late 1970s, it was little more than a pile of rocks in the water. 

“My dad was a romantic,” his son, Kai Meckeler, explained to the Philadelphia Inquirer of his late father’s vision for what is known as East Sister Rock Island, which he bought for just $25,000 from an individual who had wanted to use it to raise monkeys for science. 

Over the subsequent decades, the gastroenterologist transformed the island into an aspirational paradise, first having the volcano-shaped rock leveled off before building a home atop it. 

Then, for $750,000 in 1995, Meckeler sold the dreamy little blip to the Williford family, who made extensive additions to East Sister Rock’s offerings. 

“It was my dad’s dream to, not necessarily own an island, but to create his own completely off-grid self-sustainable home,” Wesley Williford of Frank Taylor Real Estate, who holds the listing and is the son of the seller, told The Post. 

He grew up in Miami, but his family would frequently visit the island — located a quarter-mile from the shore — on weekends.

His father added solar and wind-powered electricity (the home had previously been generator-reliant), installed a 15,000-gallon cistern and “desalinization plan” to ensure residents have fresh water, added extensive dockage, satellite internet and TV, a helicopter pad and various cosmetic improvements.

In addition to enjoying it themselves, for years they’ve also been offering it as a short-term rental, a boat included in the visit so guests can access the space. 

Now, though, they’re striking while they feel the market is hot and trying to find a buyer willing to spend big bucks for their patch of paradise. 

They’re in no rush to offload the tony hideaway in the middle of the ocean, though.

“If we don’t get the price that we want, it’s not going to be sold,” said Williford.