Elysium

From Manual of the Planes (3e):

It is the source of the River Oceanus.

It is a place of ultimate goodness.

It is a land so pleasant you may never want to leave.

Elysium is the most strongly good-aligned plane of the Great Wheel, a place of good untrammeled by issues of law or chaos. On this plane doing well by others is more highly valued than any other ideal.

The first layer of the plane is a riot of color. Visitors marvel at brilliant green meadows dotted with starburst flowers, pools as deep blue as a jay's plumage, and silver clouds drifting against a perfect sky. The plane itself seems to vibrate with its own sense of life and intensity. It is usually a peaceful place, and tranquility seems to seep into the bones and souls of those that cross it.

Elysium consists of four layers strung together by the myriad courses of the River Oceanus. The first layer is most like the Material Plane, with sweet-smelling pines and flowering trees along its banks giving way to open meadows and rolling fields. The second layer is rougher and more mountainous, and rapids and falls are common along the channels of the river. The third layer is a great marsh awash with life. The deepest layer is the sea itself and the headwaters of the great river, dotted with islands where veteran heroes of good relax for eternity.

The size of the River Oceanus varies from a braid of smaller side channels to a mighty flow that tops its banks and floods the surrounding area. Along the river are islands, low gravel bars, and rocky promontories, which are often the homes of petitioners and other more powerful denizens.

The top layer of Elysium is Amoria; it is more like the Material Plane than the other levels. Upstream on the Oceanus, the land becomes rougher and more mountainous until the traveler reaches the cascades of Eronia, the second layer. Here, steep valleys flank the river, which surges through narrow passages.

Eventually the mountains diminish and the river spreads into a great marsh alive with insects and reptiles. This is Belierin. Finally the bottom of the marsh deepens and the traveler passes into the fourth layer of the plane, Thalasia, the headwaters of the Oceanus among the Isles of the Blessed.

While the Oceanus flows between the layers of the plane, it is not a straight journey. The great river splits into myriad smaller flows, recombines, and splits again. Occasionally an offshoot of the river curls around and reenters the layer it just left.

Vision on Elysium is just as on the Material Plane at that particular time of day. Elysium shares a day and night cycle with the Material Plane and has similar (if gentler) weather. The days are warm and calm, the nights cool and comfortable.

The nights are also alive with small lights. Not only is there a river of stars overhead in imitation of the River Oceanus, but fireflies dance among the trees and fields, and luminous jellyfish swim beneath the surface of the Oceanus.