| Harold Kainalu Long Castle | |
| Birth Date: | July 3, 1886 |
| Birth Place: | Honolulu, Hawaii, Kingdom of Hawai'i |
| Death Place: | Kailua, Honolulu County, Hawaii, US |
Harold Kainalu Long Castle (July 3, 1886 – August 19, 1967)[1] was a landowner, real estate developer, and later a philanthropist in Hawaii.
Harold Kainalu Long Castle was born July 3, 1886, in Honolulu.Castle was the son of wealthy landowner James Bicknell Castle and Julia White, and grandson of Castle & Cooke founder Samuel Northrup Castle and philanthropist Mary Tenney Castle. In 1917, he purchased almost 10000acres of land on the windward side of the island of Oahu, in what was then the ahupuaʻa of Kailua, to establish his sprawling Kaneohe Ranch.[2] [3]
In 1962, he set up the Harold K.L. Castle Foundation, which remains the largest private foundation based in Hawaiʻi. He and his foundation have donated large amounts of land to educational and other public institutions, including Hawaii Loa College, ʻIolani School, Castle High School, Kainalu Elementary School, Castle Medical Center, and the Mokapu peninsula land that became Marine Corps Base Hawaii.
He and his wife, Alice Hedemann, both graduated from Punahou School; he served on its Board of Trustees (1922–1937), and their descendants have continued to attend and support the school.
Plantation Estate, his home in Kailua, Honolulu County, Hawaii, was used by Barack Obama as a Winter White House during Christmas vacations in 2008, 2009, and 2010.[4]