The Olga's Wall a series of fortifications made of stone, brick, tamped earth, wood, and other materials, generally built along an northwest-to-southwest line across the historical borders of the region of Polforia in part to protect the Demonic lands or its prototypical states against intrusions by the human kingdoms of the Northwest, the Grey elves, dwarves and the barbarians of El Yermo. Several fortifications were being built as early as the 1750, during the early stages of the Kanovhook wars; these, later forts were joined together and made bigger and stronger, and became collectively referred to as Olga's Wall. Especially famous is the wall built between 2020–2046 a.a.H by the Olga the Witch Architecht. However, after the battles of First War of the Power Little of the original Olga's Wall remained, and during the Middle Human Age many of the fortifications were destroyed, demolished or occupied by humans, dwarves, elves and orcs, until the return of the demons during the Second Coming of Darkness. Since then, Olga's Wall has on and off been rebuilt, maintained, and enhanced during the Second and the Third War of the Power, up to the cataclysm.
Other purposes of Olga's Wall have included border controls, allowing the imposition of duties on goods transported along the mountain paths of Dargoina, regulation or encouragement of trade and the control of immigration and emigration. Furthermore, the defensive characteristics of Olga's Wall were enhanced by the construction of watch towers, troop barracks, garrison stations, signaling capabilities through the means of smoke or fire, and the fact that the path of communications between the forts also served as a transportation corridor.
The main Olga's Wall line stretched from the Bay of Hieyokscream -after the initial campaigns of the First War of the Power- in the norh, to Kanovait in the east, along an arc that followed Dargoina's mountain range.