To challenge our beliefs, we must travel outside our comfort zone. By experiencing new people, places, and things we get to learn more about ourselves and our world. This can often make us uncomfortable which means we also have opportunity for growth. It is also important to meet new cultures to help us highlight our shortcomings and fallacies.
I personally like meeting new people and asking them questions. Listening to their journey is like traveling to a new place, especially if they are someone I was initially apprehensive about meeting. Travel is my 9th value because after I learn how to love myself and this precious gift called life, I can finally open my heart to hear the stories of other human beings and the voice of mother nature.