Vertan is the homeland of the Vertani. It has never been accurately glimpsed through the portal from Sapience to Vertan. After the entire debacle, the remaining Vertani military forces were either destroyed or returned through the portal (after a siege that took several months), except for a number that went with a commander named Daqsool to seek asylum in Shallam.
Not long after the portal's discovery, and well before the Vertani War, the adventurer Zenui found his way through it and onto the plane. Around the portal from which the Vertani entered, plant life was found dead and burned. Further examination of this portal was conveniently stopped by a fortress constructed around it.
Of the geography, climate, and borders of Vertan, little is known. The only region known by name to Sapience is Sorathia, the area in which the portal was established on Vertan. It is also known that the Imperial Oracles of the Vertani reside in the far eastern lands of the Empire. The thick atmosphere on Vertan is said to be poisonous to mortals of Sapience, but the hardier Vertani inversely have no trouble dwelling in our climate.