A series of caverns, originally discovered by the Agallan explorers Fedwyrr and Klars, extends from the Frozen Caves just North of Glacern to the Great Dark Forest at the base of the Green Range, occasionally surfacing in the arctic wilderness above. Travelers along the route are treated to a vast array of subterranean waterfalls, bright crystal outcroppings, and thermal plumes of a size unmatched elsewhere in Aranna.
The most difficult challenge to the travelers of these routes, other than the loose, slippery footing and narrow passageways, are the myriad of creatures that call the caverns home. Among these creatures are the fiercely territorial Trog, a race that at one time dominated the undermountain passageways that parallel Fedwyrr's Way.
Several campaigns of the 10th Legion sought to clear the Trog menace and establish a secure trade route through the Alpine Caverns. These campaigns never managed to eliminate the Trog, but a subsequent increase in a variety of other more reclusive creatures did result. The surviving Trog are considerably less aggressive, though they still present considerable danger when encountered in groups of more than two.
Maintaining the safety of the caverns requires regular Legion patrols, dispatched from Glacern, a luxury which can only be afforded in times of peace. In times of war, withdrawal of the patrols means many other native creatures return to the passageways, among them mischievous lungers, and crystalline creatures of various colors, shapes, and sizes.
