Like other essential elements, magic exists at the very heart of the WebWeaver's Universe. While the learned and the prophets argue or debate what it is and where it comes from, magic is far-reaching and extensive, but also finite... It exists on each of the nine worlds effected by it, with Orr being at the heart of that influence. However, the further away one travels from any one of these nine worlds, the more diluted the magic becomes throughout the universe.
For hundreds, maybe even thousands of years, exploration of the Nexus has been stunted, likely by the growing understanding from native occupants from each affected world, as to what these open rifts truly are — conduits into whole new worlds, and most of them far, far beyond the world and solar system early travelers were familiar with and knew. That understanding eventually expanded and with it, the growing possibility of exploitation from other, foreign civilizations.
Whether or not it was a collective effort, citizens from each of the nine most effected worlds, where magic is most prevalent, actively took precautions to control and maintain their other-world borders. There is, in most cases, evidence of conflict. For instance, there are episodic ruins that appear to be whole civilizations laid out to extinction all throughout Orr which no one has record of, but that are very consistent throughout the Everwild, where the predominance of fighting appears to have taken place. Granted, this is a vast and mostly uncharted territory, this forest, but there is a growing number of records archived in the major universities and libraries of Orr which document evidence and posit theories on the when, where and why of these fallen civilizations. Many of them cite travel through a compilation of rifts.
The Wizard, Salem Asandromere, a notable figure in Orr's recent history, is lauded by many accounts for having been responsible for the most extensive exploration and diplomatic missions beyond Orr to date. He is one of the founders of the Guild of Nyn, as well as the organizing body for the Knights of the Nyn, as well as the Order of the Tahl'Maran as we know them. For a man who merely set out to unlock the mysteries of magic, especially those mysteries considered "fringe" or forbidden, he led an extraordinary life steeped in all manner of intrigue and excitement. He is responsible for coining the name, "The Nexus of Nyn," having borrowed a portion of it from the Order of Numericals in the name of one of their goddesses (an appropriation the disciples still bitch about to this day).