Gjalerhorn is the mountain to the west of Frostblade Peak in the Howling Fjord. Gjalerbron and Rivenwood are at its southern base, the border with Grizzly Hills to its north. There is an entrance into the mountain at
- In Norse myth, Gjallarhorn is the "ringing horn" with which the gatekeeper god, Heimdallr, announces Ragnarök.
- At the peak of the mountain, the wreckage of what appears to be a rocket-powered vehicle is half-buried in the snow, surrounded by several gnome-sized skeletons along with empty bottles and fish skeletons, presumably the crew's last meal before dying of exposure and starvation.