Ley-lines are invisible (though detectable) currents in the Aether and are the main way magical energy travels from its source at various mana fonts to innervate the world. Ley-lines can flow across the surface of the land, high in the sky or straight through solid bedrock. though they do often follow naturally-occurring currents (magma flows and rivers, especially). Many arcanologists, however, maintain that it is in fact the geology of the world shaping itself around the pre-existing ley-line instead. A particularly strong ley-line deep beneath the surface of the sea-floor is considered responsible for the formation of the Chain of Glass, a series of still-forming volcanic islands far to the south.
As the Aether is key to sustaining life, ley-lines are coveted as ideal locations for settlements and farmlands.