Dwarf Roads

The Dwarven cassams that dot the underground of the world are wonders. Vast roadways tunnelled for miles and miles, large enough to transport a dragon or giants. Everyone knows what they are and what finding one means. Trouble. The Dwarf Roads are roads built by the Mountain dwarves to the east. They are grudge holding advanced folk whom despise the overworld because it whenever encounters causes problems, steals their items and technology, or allow their pesky over monsters to wander into their roads. Finding a none Dwarf in the roads is a recipe for an arrest and being sold into indentured servitude.
The Technology however may make it worth the effort. Using steam vents and Geophoria the dwarves of the Mountain have figured out crazy advancements that they refuse to share with the rest of the world. Every time someone starts using something they designed and they find out. Expect that area and land to get an influx of angry dwarves asking for their family technology's back so they can scratch your name out of their ever expanding grudge books.
It is an understood fact that the Dwarves of the Dwarf roads and the Drow of the Drow-ways are at an almost constant war.