The Lowerways, sometimes called the "Lowerdark", were a Deepways realm 10 miles below the surface of the Head of the Greatwyrm and other "Upper Worlds". Considered incredibly perilous, the Lowerways were a place that even familiar denizens of the Middleways and Upperways were loath to travel. Rumours of impossibly large, toxic, or psychic creatures came up from this realm, and some believed its tunnels lead directly into the Lower Realms.
A Common adage regarding the realm was "If you think that something is impossible, it happens in the Lowerways."