Iona is the name of a small Scottish island in the Inner Hebrides — one of the most important early Christian sites in Britain, where Saint Columba founded a monastery in 563 CE that became the source of much Celtic Christian art and the Book of Kells.
The etymology of the island name is debated — possibly from Old Norse "island of the yew tree" or older Gaelic. Iona as a girls' name is rising in the Scottish-influenced English-speaking world.
Iona reduces to two — the number of sacred island.