From Destinypedia, the Destiny wiki
The Simulant Past is one branch of the Infinite Forest simulation in the Fields of Glass, Mercury. It is a Vex simulation of the distant past, when Mercury was initially terraformed by the Traveler into a garden world and the Vex had only just arrived. It is full of Vex constructs such as the Gardener's Spire which transformed Mercury into a vex machine world. It is also home to plants known as Hermaion trees. The Simulant Past is only accessible in the story mission A Garden World, the strike A Garden World and the adventure Bug in the System.
List of appearances