The Avatar of Freya at the Rainspeaker Rapids wants you to go to the Makers' Perch and use the Activation Switch Gamma.
It is time then. Let us activate the waygate.
You will find the first switch inside the Makers' Perch in the western edge of the basin.
Beware, <name>. The titans used the perch to watch over their creations. Many of their stone servants still guard the place.