adverb
whereto
WAIR-too/ˈwɛrˌtuː/
To what place or destination.
The traveler is ready to leave, but whereto will the chosen train take her?

Etymology
Where supplies the question about place, while to adds direction toward a goal. Together they ask for a destination rather than simply a location.
More examples
- Whereto does this narrow path lead?
- She asks whereto the train is bound.
- We must decide whereto we should send the supplies.