Yes, there is a very old town called Alcantara in Spain. It is in a region named Extremadura, from where many "conquistadores" came from. It is situated in the province of Caceres, near the border with Portugal. Its main feature is an imponent Roman stone bridge over the Duero river (Al-Cantara means "the bridge" in arab). This town has about 10,000 people and it's got a web page with photos.