The Valley of Endless Soils
At the heart of Yamdallah there is a large open valley. Ringing the valley the draconic peoples have built up a sizable city, though none consider encroaching beyond a certain point on the valley itself. The significance of Aenvacara is not in a historic event or naturally occuring resource, but rather was chosen as a favorable location to begin the tradition of Lungu Magris, or the "Pilgrimmage of Claw."
Before the dragonborn chose this as their spot of meeting, the valley had no inhabitants. Indeed even hermits and vagabonds kept away from the harsh heat and dry and thin air. These seemingly unfavorable attributes were precisely the reasons that the dragonborn picked this valley for their holy site.
Each year hundreds of thousands of dragonborn travel from all parts of the known world (and a few from unknown places) to partake in Lungu Magris. With them they are each expected to carry a small sample of the soil of their tribe's current residence to dust over the Aenvacara, thus contributing to the greater whole.