each approx. 2.5 cm wide, 3.2 cm high
A pergola, arbor, or arbour is a garden feature forming a shaded walkway, passageway, or sitting area of vertical posts or pillars that usually supports cross-beams and a sturdy open lattice, often upon which woody vines are trained.
The origin of the word is the Late Latin pergula, referring to a projecting eave. As a type of gazebo, it may also be an extension of a building or serve as protection for an open terrace or a link between pavilions. They are different from green tunnels. (source: Wikipedia Germany)