While the large-scale sugarcane plantations that dominated the local economy for more than a century have all been shuttered, agricultural land remains a hot commodity on the rural Hawaiian island of Kauai.

Thousands of acres of farms and pastures once held by scions of plantation-era aristocracy are being gobbled up by new-money billionaires and global investment firms. These lands make appealing additions to an investment portfolio not only for their prime location and skyrocketing value but because they are eligible for a huge agricultural program that saves landowners millions of dollars on their property tax bills.

Recipients of these breaks include Meta billionaire Mark Zuckerberg and his wife, Priscilla Chan, who save upward of $300,000 in property taxes each year on their 1,400-acre North Shore ranch.