Union Island (St. Vincent and the Grenadines) As the sign on Union Island's shore states: Union Island is the most southerly of that crescent of scattered jewels numbering as many as 50 which comprise the state of St. Vincent and the Grenadines. Five kilometers long and half that in width, the island is positioned some 44 miles south of St. Vincent and has a population of approximately 2,000. The two main centres of population are Clifton Harbour and Ashton - names redolent of our colonial past. Clifton Harbour serves as the administrative capital of the island. Outlined against the azure skies is the highest point in all the Grenadines, Mt. Tabor (1,000 feet). Such volcanic features have inspired many to call us "Little Tahiti".