I've started reading Joel Kraemer's recent biography of Maimonides. Right off the bat, an interesting case of linguistic travel shows up. In Cordoba, the bishop's palace is called the Alcazar. This comes from the Arabic al-kasr, meaning castle or palace, as it was built on the foundations of the local Caliph's palace. So where does the Arabic word come from? Latin, castra, meaning watchpost. From castra, we get castellum, meaning fortress, which becomes our Castle, even if it is a diminutive of castra.
So from Latin Castra, we get Arabic Al-kasr, which winds up back in Spanish as Alcazar. Yes, Spanish as a Romance language derives from Latin, but this word took a side-trip through the Convivencia.