Arcadia

Arcadia is the most lawfully aligned region of the Upper Planes. It is a vast array of different natural landscapes, each completely regular and without flaw. The trees of the forests grow in straight lines to identical heights, the plains and deserts are flatter and more perfectly level than any surface made by a mortal craftsman's hand, the rivers join each other at precise right angles and symmetrical curves, and the hills and mountains increase and decrease in height in strict accordance with parabolic formulas. It is said that every secret of mathematics and numerology is encoded somewhere in Arcadia's terrain. The gods known to hold domain over Arcadia are largely gods of knowledge and law. The most famous of these is Hildegard, who is said to live atop a mountain that mirrors Mount Scivias on the Material Plane, but is completely symmetrical and without variation or flaw. Modrons begin and end their life cycles in the fields of Arcadia. In a mandala-like orchard somewhere in its depths, identically-spaced sprout fruits in the shape of perfect geometrical solids, which ripen into modrons. All at once, each crop of modrons drops from its mother plants and begins its great march across all lawfully-aligned Outer Planes, criss-crossing over the Liminal Plane and Astral Plane repeatedly over the course of the next seventeen years. At the end of their journey, the modrons ascend into the skies of Arcadia. Their automaton-like bodies dissolve into clouds, and they fall across the plane as a shower of precise, rhythmic rain.