unexplored

Sleep is something that has really been an unexplored topic cross-culturally.

With (the gap between) the church's teachings and ways of thinking being eclipsed by the Renaissance, the gap between the medieval and modern periods had been bridged, leading to new and unexplored intellectual territories.

There appear to be many unexplored matters about the motivation to reflect—for example, the value of externally motivated reflection as opposed to that of teachers who might reflect by habit.

Archaeologist Bill Kelso and his team discovered the church in a previously unexplored area of the fort in Jamestown.

The forest remains unexplored.

The island remains largely unexplored.