Hekla

Hekla or Hecla is a stratovolcano in the south of Iceland with a height of 1,491 m (4,892 ft). Hekla is one of Iceland's most active volcanoes; over 20 eruptions have occurred in and around the volcano since 874. During the Middle Ages, Europeans called the volcano the "Gateway to Hell". Hekla is part of a volcanic ridge, 40 km (25 mi) long. Cumulatively, the volcano has produced one of the largest volumes of lava of any in the world in the last millennium, around 8 km3.

Hekla in "The Sea Mother's Gift"
Although Iceland was uninhabited in 1160 BC, the effects of Hekla's eruption that year caused something like an ice age in many northern European communities. In the Orkney Island, the day Hekla first affected climate was called the Day of Darkness.

Literary comment
No modern proper names are given in the story, which is limited to the viewpoints of 12th-century BC tribesmen. The above information on Hekla comes from the story's editorial note in The First Heroes. While this note is anonymous, and appears to be written by editors Harry Turtledove and/or Noreen Doyle, it is consistent with what author Laura Frankos depicts in the story. Frankos has never issued a statement contradicting this information, so it is considered canonical.