Dream Visions is an explorer perk exclusive to Harriet Tubman. It grants a ~30% chance of revealing a single distant location during each travel leg. This ability only works when Tubman begins the travel leg at 70+ Sanity.
Revealed locations also unveil their 6 surrounding hexes. Any location on the map can be revealed this way, but more often one is selected that is already within 6-7 tiles of the party.