Gardens are essentially about public and private spaces, often referred to as vistas and enclosures.
A single garden may include both park-like, open views with focal points in the distance that may be admired by many, as well as smaller enclosed areas where shelter and privacy may be enjoyed by a few.
Sometimes a private garden is designed with many enclosed areas, laid out like rooms in a house. Garden rooms have floors and walls, doorways and ceilings, but are made from different materials from those used indoors. The entrances to outdoor rooms are gates and arbors. Both create a sense of arrival in a new space. Ideally the type and style of the materials used in gates and arbors match, or are congruent with, other garden structures such as pergolas and trellises, as well as with the home itself.
Trellises provide support for climbing plants and in the same manner as hedges, provide the walls for garden rooms. They are similar to fences because they become more dynamic and versatile if plants grow on them, as plants look different as the seasons change and as they grow in size.
Pergolas provide not only walls, but also ceilings, with the possibility of plants growing between the series of horizontal beams, to create shade. Shade, dappled or dense, adds immeasurably to the feeling of refuge.