Midgard is the accepted name for the world we call earth.
It is somewhat special in the grand scheme of things as it is both a nexus for multiple Ways, and is under the influence of two titans. Commonly called Rhea and Theia the presence of these two titans has heavily influenced the development of life and magic.
In the time before history, some terrible force drove the two titans into each other, wounding both. While the body of the fatally wounded Theia can be seen from the ground, the humans who dwell here walk on the supine form of Rhea*. This means that the beings that dwell here can draw on the power of both bodies, meaning that there is an inordinate amount of power available to practitioners of the arcane art.
*It is unknown if Rhea will ever truly wake, but if she does things will doubtlessly become 'interesting' for the people living on her skin.