Ley Lines are ancient, self-organizing dungeon structures created by the enigmatic and long gone Line People. They are also commonly referred to as Line Dungeons.
These complex magical structures are primarily known for their ability to reconfigure themselves. This can be as simple as changing its layout or as advanced as running an internalized security system. There are Ley Lines that are so sophisticated that they can generate resources or autonomous units for its own maintenance or defense.
Whatever technology was used to create Line Dungeons is lost to time. The Coven theorizes that it was advanced spell networking, but are unable to develop spell networks strong enough to fundamentally alter the structure of a location.
Squibs, appear to act as control units for the Line Dungeon, but independently do not have the capacity to replicate them.
Because of this Ley Lines are mysterious, possibly hazardous to the area they're in, and attractive to adventurers. In rare cases Ley Lines have been turned them into tourist locations.