PhD would be computer science related. Maybe related to compilers or programming languages.

I think what I'm saying is a 2-4 week holiday is a good way to test if you like travelling, and what sort of travelling you like. If you don't like travelling as in constantly moving, maybe a holiday in once place for a while might give you the cultural experience without all the hassles. Depends on what you like. I've met people doing back to back organised tours for months, not sure how they do that without going mad!