J.R.R. Tolkien and Charles Williams were friends, contemporaries, and fellow members of the Inklings. They both invented secondary worlds in which to set their stories, poems, and myths--and they both made maps! Indeed, each imagines that his other world is actually a pre-history to or alternative history for our own. We will take a brief look at JRRT's Legendarium and CW's Arthuriana, asking how they developed the geography, history, demographics, and cultures of their imagined worlds, how those related to the primary world, and what significance or symbolism each invited readers to infer from their invented lands.