Hekla (hĕkˈlä) [key], volcano, 4,892 ft (1,491 m) high, SW Iceland. Since the early 11th cent. more than 20 eruptions have been recorded; the worst occurred in 1766 and the most recent in 1947. Hekla emits steam and has several crater lakes. In medieval Icelandic folklore Hekla was believed to be one of the gates to purgatory; it is also a legendary gathering place for witches.