Although their styles, materials, and name may have changed, the purpose of pergolas has remained the same for over 3000 years. The earliest known surviving garden plan, dating back to about 1400 BC, belonged to an Egyptian high court official of Thebes; details a pergola over the entry way into the garden. They have become popular in the United States in more recent years. With our poly roofs, our pergolas are the perfect place to relax and cool off on those hot Oklahoma days.