Peta Mathias gets off the plane at La Paz, Bolivia — and the world's — highest airport. She steps straight into poverty, altitude sickness, stunning scenery and likable people. Her Bolivian experience includes sub-zero temperatures, uninspiring food and the infamous mining town of Potosi. But as she writes in her diary, adventure travel means, "no skidding over the surfaces, no observing through Prada sunglasses, no shirking from the reality of the culture. In that sense the journey is unforgettable because it's so intense and puts you right up against the wall."