Here, for example, is the Iglesia del Cristo de la Luz in Toledo, which is actually a former mosque built in the year 999, later converted into a Christian church. It was after this that the apse was added to the original building.
As well, I wished to share with readers some images from the remains of the 7th-8th century visigothic Ermita de Santa María (Quintanilla de las Viñas).
First, to give some context here is what we are seeing:
Here then are some details of this fascinating structure:
Finally, I wished to show this delightful little church of San Pedro de la Nave in El Campillo, Spain.
Image sources: Skyscraper City #1, Skyscraper City #2 and Wikipedia