|“||... There we were, moored up by the Ice Needles, when old Utgard-Loki blew its stack, cracking the outer facade of ice.||”|
|— Arngrim Dammen on one of his escapades|
Based on the commentary of Arngrim Dammen, Utgard-Loki is an active volcano next to the Ice Needles. Based on his commentary, Utgard-Loki contains the Labyrinth of Lost Souls beneath or next to it. The volcanic and geothermal heat is presumably the source of sulfur and heat for the adjacent Jotun Hot Springs.