Elvas, Portugal

The attractive hilltop town of ELVAS was long one of Portugal's mightiest frontier posts, a response to the Spanish stronghold of Badajoz, just 15km to the east across the Rio Guadiana. Its star-shaped walls and trio of forts are among the most complex and best-preserved military fortifications surviving in Europe. The town was originally re-taken from the Moors in 1230 and withstood periodic attacks from Spain throughout much of the following three centuries.

These days it's much quieter in small-town Elvas. Spanish day-trippers pop over to see the steep cobbled streets and mansions, and sit in the restored central square ringed by cafés. The population is only around 25,000, all of whom appear to descend upon Elvas's Monday market – a vibrant, chaotic affair held just outside town behind the aqueduct.