Rain Isle was discovered in LY 884, by an expedition sailing northeast from Ship. Its coastline is roughly 3700 miles around, making it the largest isle thus far discovered on The Land. In fact, according to guidelines established in 860, a year after the discovery of Atlast Land, the landmass should have been classified as a continent rather than an isle. However, a renewed debate was sparked in which the settlers of Port (Rain Isle's first and so far only village) insisted that in spite of having a longer coastline than Atlast Land, it actually had less land area, because of the shape of its coastline. (The shape of the isle is reminiscent to that of a raindrop or tear, which is how it received its name.) It's because of the northern cape being relatively narrow that the total area of the isle is less than that of Atlast Land.
Much of the southern part of Rain Isle is dominated by Rain Forest, the name of which has led many Portians to joke that it should not be confused with "rainforests," as the isle is set in a much cooler climate than that of rainforests, and therefore contains different species of both flora and fauna. (The most notable fauna of Rain Isle are moose.) Much of the area north of Rain Forest contains marshland, where plants including marshlilies, anidalas, and sprayberries were first discovered.
Rain Isle serves as the intersection of Port Sea, which borders the isle to the west, North Ocean, which borders it to the east, and East Ocean, which touches a small segment of the isle's southern coast.