Torrejón de Ardoz, Spain

With a population of 143,526, Torrejón de Ardoz is no sleepy suburb. This industrial hub on Madrid's eastern edge has experienced rapid growth, attracting waves of workers seeking opportunity. But the breakneck development has come at a cost - the city's bureaucracy is a persistent headache, and the semi-arid climate can be harsh.

The European Union's satellite agency and Spain's space program are based here, underscoring Torrejón's role as a technology center. However, the city's heyday as an industrial powerhouse has waned, and the loss of the American military presence in the 1990s was a blow. Still, new shopping malls aim to compensate for the decline in manufacturing jobs.

Torrejón is best suited for those seeking an affordable, well-connected alternative to the Madrid metro area, with a tolerance for administrative hassles and unpredictable weather.