A Timber Trellis (Pergola) is an outdoor garden feature consisting of a framework or an archway with vertical posts or pillars that support crossbeams and open lattices or rafters. Timber Trellis (Pergola) are often used as a decorative structure in a garden or as a shaded walkway or sitting area. They can also be used to support climbing plants such as vines, creating a natural and beautiful canopy.