Juggernaut

A small city housed in the axle of a titanic wheel that crushes everything in its path.


 * The wheel is five kilometres wide and ten kilometres in diameter.
 * No outsider has ever been inside it.
 * It can turn.
 * It can roll up hills, mountains and even deep underwater.
 * It rolled northwestward across Genertela in the Imperial Age
 * It was once in Pamaltela
 * It disappeared underwater for centuries.
 * It is currently in Genertela

Source: Glorantha: Introduction to the Hero Wars, Elder Secrets Book