In the MMORPG, Eggman Origin, four pillars are seemingly equidistant from the center of the map, creating a square. These pillars are referenced by multiple eggs located in the map, making them a major symbol.
Behind You claims that "our" grandpa built the pillars. The context of "Our" isn't made clear. For whatever reason he says that he will mount one and scream. Once again the specific kind of scream (of joy or pain) isn't said.
Distant Egg, the second egg to mention the pillars, is on the top of the pillar in the back-right of the map. You speak to him by reaching the tip of the pillar's shadow, and interacting with his silhouette.
Distant Egg is the only known creature to have made it to the top of the pillars. However, it is alluded by both eggs that it is possible.