Named after, and modified from, the Sea of Rhûn in Tolkien's Middle-earth. The Sea of Rhûn is a large saltwater lake of roughly 1,000,000 km² (arguably a full-fleged ocean), seperating Midgard from the lands to the east, referred to as Utgard (out-yard). It is this lake that Lif sets out to cross at the end of Random Kingdom.