“There seems to be a public image of any given city which is the overlap of many individual images," American urban planner Kevin Lynch once said. "Or perhaps there is a series of public images, each held by some significant number of citizens,” he added.
Following this remark, in his book "The Image of the City" (1960), Lynch begins an analysis around the elements that constitute what he considers to be the image of the city. While introducing, describing, and illustrating these elements as physical, perceptible objects, Lynch considers that other non-physical factors such as history, function, or even the name of the city also play a significant role in the construction of this imageability.
These elements form a set, and none of them can be isolated or be applied exclusively to a specific urban context. For example, the Place Charles-de-Gaulle in Paris, where the Arc de Triomphe is located, could be both a node and a visual landmark, just as the mountain range on the outskirts of Antofagasta, Chile, can be considered both a boundary and a landmark. In other words, none of the elements proposed by Lynch exist in isolation in the real case, and therefore the author concludes that although his analysis begins with the differentiation of the data into categories, it must end with their "reintegration into the whole image."
The elements that make up the image of the city can also be recognized and interpreted in different ways depending on the observer and the context in which they are examined. So the following aerial images presented to illustrate Lynch's five elements of city image reveal a shifting, overlapping categorization associated with a specific point of view.
Lynch describes paths as the "channels along which the observer customarily, occasionally, or potentially moves." These channels may be streets, boulevards, and avenues, as well as waterways, railroads, or any other means used for moving through the cities. Aerial photographs of Brussels, Belgium, and the suburbs of Dagenham, England, reveal the differences in the patterns of their streets.
Edges are linear breaks in continuity, barriers, more or less penetrable, that can close one region off from another, or join them together. They can be walls, water bodies, railroads, etc. Two different examples of edges are the walls around Lucca, Italy, and the boundaries created by the mountain range and the coastline in Antofagasta, Chile.
Districts are determined by their two-dimensional extent and are a very common formal division of city areas. These sections are used in many cities and are defined by geographical region but also by one or more common, identifying characters. In central Madrid, Spain, it is possible to distinguish the neighborhoods from the different plot sizes and street layouts, similarly to the central region of Thessaloniki, Greece, which was rebuilt following a major fire that destroyed a large part of the city in 1917, adopting a more geometrical and regulated plan.
Junctions, a crossing or convergence of paths, and moments of shift from one structure to another are some of the examples of city nodes cited by Lynch. Although these elements always evoke the idea of movement, the author claims that nodal points can be both connections and concentrations, as is the case of a street-corner hangout or an enclosed square. These features become clear when observing the aerial images of La Plata, Argentina, as well as the Plaça de Tetuan in Barcelona, Spain, because both show nodal points formed by the intersection of streets and the presence of squares.
Landmarks are different from nodal points because they are not penetrable, they are external. Although it is possible for a building to be a landmark, it is used by the observer only as an external visual reference. Landmarks can be of smaller or larger scale, ranging from signs to towers, mountains, or even the sun. Two very famous examples of landmarks are the Statue of Liberty in New York, United States, and the Asinelli and Garisenda Towers, in Bologna, Italy.