The World Pillar is a major landmark in Gravity Rush and its sequel. It is a massive, tree-like pillar that stands in the middle of the sky, with spiral-like patterns along its height. Various protrusions grow from the "trunk," some tree-like and some less so, with the protrusions becoming more varied and bizarre the further up or down the Pillar one travels. Several of these protrusions act as entrances into the innards of the Pillar.
The pillar possesses a time dilation effect: the further up the pillar one goes, the faster time travels. At the base, time flows much slower.
At its base lies the city of Boutoume, a city stuck eternally in the past. It is built among the World Pillar's roots, which hang from the ceiling of a massive egg-like "seed," its broken shell exposing it to the abyss outside.
Some way up the Pillar can be found the city of Hekseville. Additionally, the city of Jirga Para Lhao exists somewhere at approximately the same "altitude." Here, time flows at a normal rate, relatively speaking.
At the top of the Pillar is located the kingdom of Eto, from which Kat, there known as Queen Alua, hails. There, time flows at such a rate that one hundred years elapsed during the events of Gravity Rush and Gravity Rush 2.
Within the Pillar, there are zones where gravity is altered, stripping Kat and Raven of their ability to shift gravity (or, as in Gravity Rush 2, a large portion thereof). The insides of the Pillar's lower half are vaguely skeletal in design, with white branches spanning the diameter and rib-like structures lining the lowest reaches. Above Hekseville, the insides of the Pillar take on a more plant-like appearance, with trunk-like inner walls and floating structures that resemble germinating seeds.
In Gravity Rush, if Kat ventures too close to the Pillar, she is teleported back to land by Dusty. However, in Chapter 12, she can climb up the Pillar's outer surface for a good distance before being teleported back. In Gravity Rush 2, Kat can freely stand on the outside of the Pillar at any time; however, the height limit still remains, outside of Chapter 21.
According to Singlor, the World Pillar is slowly being pulled towards the massive gravity storm at its base, which is actually a black hole comprising The Darkness. The storm is not actually moving at all. This also explains the time dilation effect, since the immense gravity of a black hole will make time pass slower the closer one gets to it.