Forge of Creation is the birthplace of Celestialsapiens and home of Mother Celestialsapiens. It is arguably the most important place in the known Ben 10 multiverse, a place that creates Omnipotent beings such as Ben 10's Alien X, with the power to recreate the entire universe after destroying it.
A pregnant Celestialsapien has a small glowing white orb in her hands with a baby Celestialsapien growing inside it. According to Dwayne, it takes a baby Celestialsapien tens of thousands of years to develop. Celestialsapiens are immensely powerful beings with the power to control reality. This ability is so powerful, merely thinking something makes it a reality. However, a Celestialsapien cannot do anything unless a majority or all of its personalities agree on it. They have spent eons debating before using any of their powers.
A baby Celestialsapien does not have multiple personalities, but it is also not mature enough to use its power. Aggregor tried to take advantage of this by absorbing a baby Celestialsapiens power to become a mighty god. Not riddled with dual personilities, Aggregor would have become impossible to be defeated by a mere mortal, and as with the powers of a Celestialsapien, he would have been immune to the effect of any manner of reality bending of any magnitude.
Each Celestialsapien has 2 distinct personalities inside them. There needs to be a 3rd agreeing for them to do anything. So while they are arguably the strongest beings in the multiverse, they are handicapped. Even when Forge of Creation was invaded by Aggregor to feed on the energy of a newborn Celestialsapien, the Mother Celestielsapien spent the entire time deliberating on what to do in the pocket dimension where her two personalities exist.
As the Forge is surrounded by a chrono-randomization barrier, it is impossible to get. Only the Celestialsapiens and Paradox can reach the Forge. Although, anyone using the Map of Infinity can do the same. Paradox himself is not allowed to come within 500 light years of the place. Alien X's split personalities Bellicus and Serena almost destroyed Paradox (by coming into an agreement), when he appeared in the dimension, before he managed to change Ben back to his human form.