Maggie's Farm

Spain is a great place to look at Moorish architecture. Sometimes it is referred to as Islamic, but Moorish is more accurate. The horseshoe arch, for example, was borrowed from the Christianized Visigoths who ran the various Spanish kingdoms before the Moslem Moors successfully invaded Iberia in the 700s.

Even after Christian kings had their long reconquista, but while Granada was the last Muslim outpost (until 1492), Moorish architects and craftsmen were in demand throughout the Iberian peninsula because the style was so popular. That post-Reconquista style is referred to as Mudejar, which often combined Moorish with some Gothic and Renaissance styles.

Good summary: Islamic Architecture of Andalusia.

My pic of a courtyard in the Alcazar in Seville is Mudejar. In Moorish architecture, it was usual to use scavenged old Roman columns for their new buildings.