Rift Beacons were objects that were used to alter Locations and bring back old and new locations. They were first introduced in Season X , when The Scientist used them to alter Neo Tilted into Tilted Town, a Wild West version of Tilted Towers. The energy used from the Rift Beacons came from the Zero Point.
Rift Beacons appeared in random locations every week, knowing that specific location will change. When new challenges came out, that specific location would have changed into a new location or an old location.
In Chapter 2: Season 4, they were repurposed by Tony Stark to spawn in new POIs and a ring of them were placed around Frenzy Farm and The Orchard. When Stark Industries was created as a result, they powered down.