The Emanant Skylight are three locations in Enkanomiya. These locations notably have a pool with Ghostfish during Evernight. Using these Ghostfish will lift the Traveler up towards a Time Tunnel which will take them to one of the three Locus subareas.
The Ghostfish will not appear, even during Evernight, until the Traveler has started the The Three Great Martial Trials world quest.
The Emanant Skylights are guarded by Bathysmal Vishaps: