What's the most natural way to complete this question (the person asking this question wants to know the name of a place)?
If I keep going south from here, […]?
"End up" is natural in this context (for my American English). I would say:
If I keep going south from here, where will I end up?
This puts the burden on the answerer to decide how to answer the question (as opposed to "which place will I reach?" which limits answers to places as @n0nChun says.
"Where will I be" to me seems slightly less open-ended than "end up", though almost the same. I don't think I've ever heard "get to", but I suspect it's regional and equivalent to "end up". I don't see a fitting wiktionary definition for "get to" though.
I think both of the following are correct. Others, correct me if I'm wrong.
If I keep going South from here, what place will I reach?
If I keep going South from here, where will I get to?
On a sidenote, the answer to the second question may not specify a particular place. Like, the person may say, you'll get to a dead end. If you really want a particular place, I guess you should frame your questions more specifically like in (1)