Pergolas are a shady, garden structure whose beginnings date back to ancient Egypt, Greece and Rome, and were common features in early Renaissance gardens throughout Europe. Their primary purpose was to provide shade on walkways, terraces, or pools. The earlier versions were often constructed from stone pillars with wooden cross-beams with a lattice roof. It was common to see ivy, grapevines, or other climbing plants winding around the wood, and filling the open spaces between the lattice. Today they are often constructed from pressure-treated wood or cedar. The many varieties of maintenance-free lumber products are also widely used. They give the look of wood, but never need painting, resist rot, peeling, and fading, and are available in a variety of colors.