Rose Window Mission San Jose was known as the "Queen of the Missions." It was the largest of the San Antonio missions, and was (and is) quite beautiful. One of its unique features is this ornate "rose window." The origin of the name is unknown.
Intricate Arabic designs deliberately incorporate a mistake to acknowledge that no one is perfect except God. Probably the artisans need not have bothered, given people's natural imperfection, but the sentiment is worthy.