What are borders? Are they simply political and geographical, marked by posts, walls and fences, or should we think of them more broadly? In his third book on travel, history and culture, college professor, historian and journalist David Mould rambles through a dozen countries in Asia and southern Africa by car, bus, train, shared taxi and ferry, exploring what borders mean to their peoples.

Many countries are the artificial creations of colonial powers. Their borders, set by surveys and treaties, took no account of topography or the ethnic groups that were cobbled together. There are also borders within countries, defined by race, ethnicity, or caste. Borders may be physical and economic, even perceptual—the borders of our minds.

On his travels, David faces shakedowns by border guards, finds old-time religion in Malawi, revisits the legacy of apartheid in Johannesburg, traverses the rivers of Bangladesh, wanders through the ancient kingdoms of Nepal, explores Malaysia's troubled colonial past, sets off security alarms in Karachi, counts yaks and discovers dinosaurs on the Mongolian steppe, savors the cuisine of Georgia and fulfills a Dr. Zhivago fantasy on the Trans-Siberian Railway.