The World Spring

The World Spring is a massive volcano, towering over any other mountain. It is the first of the Seven Natural Wonders of Anu and is located at the northern tip of Excaria and the smoke rising from its maw visible from across the continent. While "The World Spring" is the name that was spread by the Old Empire and the name most commonly associated with it today, the first Dwarves who wandered down from the volcano called it "Aul-Kelda'Kuhl".
In the days before the Old Empire, the empire of these first dwarves, called Aul-Duroth'Tahr was one of the most prosperous societies in the old world of Anu. The dwarves of Aul-Duroth'Tahr tunnelled through the World Spring and the surrounding Blackrock Hights Mountains establishing many great mountain holds and a impressive network of tunnels to connect them. The greatest of them, jewel of Aul-Duroth'Tahr and its capital was Kuh'Karakzath.
The dwarves isolated themselves in their holds and tunnels and collected great hoards of gems, precious metals and artefacts of legendary craftdwarfship. Over time, other peoples created great societies and empires, some of which began to covet the great riches of Aul-Duroth'Tahr. This started the War of the Five, which saw the dwarves of Aul-Duroth'Tahr, the ancient pre-imperial Humans and High-Elves, the Feyed Eladrin and the Shortfolk in near constant conflict.
It was this war and The Endtimes following it that brought down the once mighty Aul-Duroth'Tahr, ultimatily being conquered by the newly established and rising Old Empire. The Imperials continued the mining operations and across the ages investigated the true nature of the World Spring. They determined that all land of Anu was created from the magma spewing forth from its maw.
Far more importantly; the magma carried up is brimming with raw magical energy, likely the source of most if not all magic on Anu. Where this magic is coming from not even they could definitively answer. 
This special magic, dubbed Primordial Magic by the Imperial scholars, has many fantastic properties, exceeding even the imagination of the greatest mages. Most notably it powers the World Forge. Originally constructed by the dwarves of Aul-Duroth'Tahr, it was later repaired and improved by the Old Empire. It is the only known place in existence where Eternium can be forged.