Libertador General San Martín, Argentina

With a population of just 49,267, Libertador General San Martín is a sleepy outpost on the Argentina-Uruguay border. The sole point of connection between the two countries is the 5,366-meter Libertador General San Martín Bridge, a towering cantilever structure that opened in 1976 at a cost of $21.7 million. Bureaucracy is a persistent headache, as the bridge and its access roads straddle the jurisdictions of both nations. But for those willing to navigate the red tape, the remote location offers a respite from the bustle of Argentina's big cities.