The least expensive country for travel in South America also offers some of the continent's grandest adventures. First, swallow the bitter pill of the $135 visa fee US citizens pay to get into Bolivia (we do it to them, so it's only fair). That done, marvel at just how cheap food, lodging and tours are here, especially compared to neighboring Chile. Very decent hotel rooms can be had for $30 a night in most spots and transportation costs are bottom of the barrel because Venezuela subsidizes fuel prices. Land in La Paz and you're already at 12,000 feet, well on your way to acclimatizing for the summit of nearby Huayan Potosi, one of the world's most accessible 20,000 foot peaks. Mountain bikers tempt fate with a screaming ride down North Yungas Road (aka Death Road), a descent from 16,000 feet to 4,000 feet over the course of 40 miles that takes nearly seven hours.