We should offer a feature to create, or integrate travel maps (somewhat like TripAdvisor). It will surely allow us to gain more insight into the destinations fellow members have traveled, and can help along with.
I think there are many sites with such feature already. Our point is a Q&A site, not the Plan-A-Trip site. If user wants to point out some travel plan, he can share the URL to the google maps or something.
Also Plan-A-Trip question are very uncertain, users provides many options, and this is not how I think this site should work.
What may be interesting would be a "world heat map" indicating for what country/region of the world a given user is active on the forum.
ie. a user who is only active for questions related to Croatia would have all the countries greyed out except Croatia coming up in red.