An immense subterranean network carved through divine bone, abandoned cities and caverns that predate every surface kingdom.
Overview
The Deep Roads are too straight to be natural and too large for any known people. They pass through caverns, under seas and sometimes through the pale interior of structures theologians identify as Earin's bones.
Mile pillars emit a weak blue light when approached, though their numerals follow no surface sequence. Side roads lead to sealed stations, fungal valleys and cities built upside down into cavern roofs.
History
Fragments of several empires used local portions of the Roads, but none controlled the whole network. After the Underdark wars many entrances were buried or placed under religious ban.
The Opening began when High Artifice survey engines forced three sealed gates simultaneously. Trade returned, followed by prospectors, armies and things that had once relied on the gates remaining shut. The resulting age transformed the known map.
The present record
Licensed caravans travel between guarded stations, cutting months from surface journeys. Beyond them, unregistered branches remain the domain of scavengers, exiles and deep polities that reject surface authority.
Since the Lantern was freed, the mile pillars have begun counting down.
Notes and record
This article combines campaign record, spoken lore and the mythic account preserved in the Earin archive.