The Great Orm was originally a system of natural caves located in Dimrella range, over the Hammer Falls, a range that ends the eastern side of the Iron Hills. Their genesis are dedicated to the ancient dwarf Skírnismál who after his quest to free the mountains of orcs, and giants, is said to have founded the great structure.
The caves lead into a subterranean abyss: the Orms Chasm: some fifty feet wide and of indeterminate depth, its only entrance crossed only by The Dwarven King's Bridge, "a slender bridge of stone, without kerb or rail". It forces any group wishing to cross to go in single file, limiting the power of any attack, and acts to test the mettel of all who will will have dealings with the Dwarven Elders and Sworn brothers of the Ancestors of Adamant, who make the Great Orm their abode.
The Center Forge lies on the Eastern edge of the Dimrella range, while the the Orms Chasm stretches all the way to northern region of the Giantwalk. The original caves of the Great Orm, where the first Dwarven city-kingdom was founded after the loss of the Underholm, have since been swallowed by the Orders needs.
The river Silverbeltine feeds the Hammerfalls; and from their heights can the whole of Torins Bay be seen, including the settlement of Tarkett. The Silverbeltine pools below in the Mirroredmer, where the great dwarish architects of ages past have built a giant aqueduct form white marble, that feed the city of Tarkett with water for its many fountains. It is said that the first rite of passage for a potential sworn brother is to swim up the entirety of the Silverbeltine, from Tarkett and into the heart of the Great Orm itself.