You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Muslim_world

Context:
Distinguishing motifs of Islamic architecture have always been ordered repetition, radiating structures, and rhythmic, metric patterns. In this respect, fractal geometry has been a key utility, especially for mosques and palaces. Other features employed as motifs include columns, piers and arches, organized and interwoven with alternating sequences of niches and colonnettes. The role of domes in Islamic architecture has been considerable. Its usage spans centuries, first appearing in 691 with the construction of the Dome of the Rock mosque, and recurring even up until the 17th century with the Taj Mahal. And as late as the 19th century, Islamic domes had been incorporated into European architecture.

Question:
What physical characteristics are common in Islamic architecture?

columns, piers and arches