As such a climactic site, it is the end of the first portion of the game, and the last chapter before advancing to the Southern Continent.
The Barred Gate got its name after it was sealed by Dura many millennia ago after the great invasion. It is the source of all greed, jealousy and loathing that exists within the world. It is from here that Annih's children, the Hypogeans broke the seal and poured forth from it into the mortal realm. Its evil is immense and radiates outward, corrupting anyone and anything without the willpower to resist its calling.