Alcántara is a small town in north-west Extremadura, not far from the Portuguese border.
Numerous mansions, churches and convents line its streets, a sure sign of the town’s historical significance, but most tourists come to Alcántara to see the Roman bridge over the River Tajo.
194 metres long and with six arches, this bridge is an immense engineering feat, given the terrain and the means at the Romans’ disposal.
Once in Alcántara, I thoroughly recommend a further excursion into Portugal to visit Monsanto, perhaps the most outstanding mountain-top fortress with accompanying village in all of Portugal (and there are a few superb examples mentioned elsewhere in this guide, such as Marvao, Sortelha and Monsaraz.
The advantage for you is that many of these castles tend to line the Spanish-Portuguese border and are thus easily accessible from Extremadura, albeit often via dodgy country roads. My experience is that Alcántara to Monsanto is currently best travelled via the border crossing near Monfortinho, although road-building seems to be progressing in this area and up-to-date advice from the locals may be useful. I hope you do make it to Monsanto, as the setting is unforgettable.