Great Glacier

The Great Glacier is a massive stretch of ice that travels far past the northern borders of any nation. It is a land of ice and snow, a cold and barren place.
The further north one travels on Faerun the colder it gets, until eventually the land is encased in a never ending winter. The Great Glacier was once a vast and cold sea. It is said that when Ulutiu, father of giant kin, laid himself to rest in a barge among the sea. His barge sank and his amulet froze over the vast ocean creating the Great Glacier. Many explorers have searched for his tomb, but due to the harsh and unforgiving lands of the glacier, none have been successful, and only a few have lived to tell the tale.
There are communities that live upon the Great Glacier though, various settlements where some humans have adapted to the cold climate. Almost all of the humans that live in these settlements are followers of Ulutiu, with a large number of Druids belonging to the Circle of the Land. These societies typically only contain a few hundred residents, and are located across various basins that are more forgiving than the surrounding wastes. Due to their location, these settlements are remote and isolated, preventing the establishment of trade routes between them and their southern neighbors.
In these basins there are a large variety of wildlife, anywhere from wolves, to arctic foxes, to even mammoths. Outside of these barrens in the frozen wastes, are considerably more dangerous creatures. There are Frost Giants, Ice Mephits, and even White Dragons that make their home in this land of ice.
Travel through this region is difficult and harsh, but it is one that hasn't stopped explorers from attempting to cross this land. There is no defined map that marks the northern border of this area. The tales only tell that the further north you go, the colder it gets, so much that even dangerous creatures made of ice dare not venture too far north in this land.
In the southern part of the glacier is a region referred to as the Ice Spires. This region consists of tall and snowy mountains, and contains the ruins of Voninheim. Voninheim was a citadel that was home to countless giants, it was believed to have been a beautiful and massive structure that contained all sorts of riches and artifacts collected by the various giant races. Unfortunately, the citadel was destroyed by the encroaching ice and snow of the Great Glacier around the year -2550 DR. It is now reduced to ruins that have been gradually worn down and buried over the centuries. Travelers have aspired to explore the citadel, but for centuries there have been claims of a large White Dragon that has made its homes within these snow encased ruins.
Though while the land may appear bleak and barren, occasionally during the months of Uktar and Nightal the sky will light up with an assortment of colors at night. It casts a glow that illuminates the white land below. It is said that these lights are the souls of Ulutiu and Othea reuniting within the Astral plane over this land of endless ice. Druids of the Circle of the Land believe this to be a holy time, and will engage in song, dance, and feasts for the night in celebration of Ulutiu.

White Dragons are powerful chromatic dragons. They usually are solitary creatures that prefer arctic climates and are well adapted to live in lands such as the Great Glacier. They can travel across ice and up mountains with ease and they are also exceptional swimmers, White Dragons commonly dive in the northern oceans as their diets largely consist of aquatic creatures, even whales. After killing a creature a White Dragon will carry it back to its lair to allow it to freeze before consuming it.

White dragons are smaller than other chromatic dragons and are more solitary, they tend to be opportunists and scavengers. So while sightings of a White Dragon may be rare, they are still incredibly dangerous.