A widespread motif in archaic cosmologies that has received little attention among scholars is the idea that the sky is formed of a solid substance and that it contains one or more openings, that enable “traffic” between the regions above and below. This article presents a cross-cultural documentation of this motif and argues that the notion of “sky holes” derived from observations of aurorae or “polar lights,” specifically from auroral arcs and coronae. The phenomenology of these types of aurorae also sheds light on a number of related beliefs—that the hole is situated on the horizon or near the celestial pole; that it frequently shuts and opens again; and that the sun or another light shines through it.