"What do we know -- what does anyone know -- of the things the jungle may hide? We have dim rumors of great swamps and rivers, and a forest that stretches on and on over everlasting plains and hills to end at last on the shores of the western ocean. But what things lie between this river and that ocean we dare not even guess. No white man has ever plunged deep into that fastness and returned alive to tell us what he found. (...) Who knows what gods are worshipped under the shadows of the heathen forest, or what devils crawl out of the black ooze of the swamps?" -- Robert E. Howard: "Beyond the Black River"
Also called the Pictish Wilderness, the far western region of the world continent, lying west of Aquilonia, north of Zingara, and south of Vanaheim. The Aquilonian frontier of Pictland seems to have fluctuated between Thunder River in the east and Black River in the west. The land in between, Westermarck, was rather optimistically deemed a part of Aquilonia.
The coast of Pictland, some 1300 miles long, had not a single port city. It was the domain of the Sea-Land Picts, who had small villages and were on a lower cultural level than their inland brethren. They did not go to sea, but apparently scavenged the strand for walrus and whale carcasses, which yielded ivory that could be traded.
Interior Pictland is described as a "howling wilderness". It is presumed to have been a slowly rising coastal plain, a vast marine forest with mild winters, broadleaf to the south, mixed with conifers to the north -- humid, rank, and tangled with briars, thick, shrubby undergrowth, ivy, and other vines.
The saber-tooth tiger and other large carnivores such as panthers, venomous pythons, wolves, cave-bears, and dragons made life interesting for the forest-dwelling Picts. The woodland glades were the home of elephants, antelopes, and deer, including the giant elk. The abundance of fur-bearers encouraged the Picts (who went more or less naked) to hunt pelts and trade them to the civilized people in the East.
Although Pictland was called a wilderness by the Hyborians, it seems to have been a virtual paradise to the hunting-and-gathering Picts, who throve in it during the 8,000 years following the Cataclysm.
References: Hyborian Age I-II, Treasure of Tranicos, Beyond the Black River, Wolves Beyond the Border, Conan at the Demon's Gate.