The walled coastal town of Al Zubarah in the Gulf flourished as a pearling and trading centre in the late 18th century (Unesco website)

From the 13th to the 16th century, the merchants of Kilwa dealt in gold, silver, pearls, perfumes, Arabian crockery, Persian earthenware and Chinese porcelain; much of the trade in the Indian Ocean thus passed through their hands. (Brief description)