The name Tarleaux refers to both a continent and the planet on which that continent resides. Shipbuilding has not advanced beyond simple canoes and barges for any of the civilizations on Tarleaux (the continent) and it does not seem to have occurred to anyone that other landmasses might exist or that the oceans might not continue forever.
Tarleaux is dominated by a mountain range, the Mathu Peaks, that splits it into two sides. Both the Northern and Southerns extremes of the range are dense, while in the middle of the continent there are a number of relatively flat passes between clumps of mountains.
Most of the continent's significant waterways flow either westward or eastward from the Mathu peaks to the sea.
The continent is cold in the south, warm in the north. Strong prevaling winds blow heavy clouds easterly but are largely blocked by the Mathu Peaks, resulting in a western side that is quite wet and an eastern side that is comparatively dry, especially at the northern and southern ends.
Tarleaux is divided into a number of autonomous regions with their own political systems, customs, and other features that bind them as nations: