Pergolas are freestanding or extensions of buildings. They are used as sunbreaks, to provide airy shelter for dining and as supports for climbing and vining plants such as grapes, clematis and climbing roses. There are many different designs of pergolas. One of the design that can create different look is arched pergola design. Instead of using flat beams to top your pergola, create the top arched pergola design. An arch provides a dome-like curve on top of your pergola to add airiness. Use redwood, steel or iron to build your arch. You can buy ready-made arches made of weather-resistant steel and iron from a garden and home improvement stores. Using this style can give your garden a rustic feel. This type of pergola is a good choice for entryway to the garden or as a pass-through.