On 1st November 1755 the Great Earthquake surprised those in Lisbon that at about 9.40 am, when most of the people were praying in churches to celebrate All Saints’ Day. In the following days people had to deal with fires that were raging throughout the city. Roads and buildings that disappeared were replaced by a desert of ruins and ash.

Despite the big shock that followed the disaster, considered the largest earthquake in human history until the 20th century with a magnitude of 8.7 on the Mercalli Scale, the catastrophe was converted into an extraordinary opportunity for a city to enter the modernity.

The reconstruction program had been preceded by a period of eight months to elaborate proposals for the new Lisbon: the selection criteria gradually led to the decision for an abstract project, which gave priority to the overall urban organization over the architectonical and functional singularities of the buildings. Rational criteria based on hygiene and preventive measures in the event of a natural disaster were based on a different organization and functionality of both public and private spaces. The century of Enlightenment in Portugal came from Lisbon.

The main feature of the rebuilt city was the flexibility that the Portuguese engineers and architects had in adapting the ideal plan, conceived as a regular grid of longitudinal and transverse axes, to the characteristics of the site, as in the case of Rua Augusta, the main street which connects in a north-south direction the popular Square of Rossio with Comércio Square. To integrate the two squares into the project and preserve their original location, Rua Augusta constitutes the symmetrical axis of Comércio Square, as it is located exactly in the middle of its northern side, a point also marked by the imposing triumphal arch, while the north end of the Rua Augusta axis does not coincide with the median axis of the south side of Rossio, rather the Rua Augusta-Rossio conjunction point is located in the south-east corner of the square, whose median axis is marked by a discrete arch in late eighteenth-century forms that marks the beginning of Rua dos Sapateiros, a secondary street parallel to Rua Augusta (the plan includes a hierarchical organization of the streets, divided into main, secondary and cross streets). The expedient made it possible to regularize Rossio, which was wider and slightly rotated in a south-east direction, maintaining its elongated and narrow conformation despite the absence of the large complex the All Saints Hospital which occupied the entire east side, complex which was destroyed by the Great Earthquake and which was decided not to rebuild. The overall ratio of the urban grid is thus preserved, while including some urban elements of Lisbon before the catastrophe of 1755.

The utopian element of the reconstruction plan lies exactly at this conjunction point between the theoretical model and its realization, where the territory is. The Portuguese ability to read the territory derives from the centuries-old experience in founding new cities on lands that are still almost unknown on the European continent, an experience that gave the Portuguese a great advantage in terms of technical knowledge and methodologies for building a city in other countries. The legacy of this praxisis still present today, as we can understand when the Portuguese architect Carrilho da Graça states that in Portugal it is easier than in other countries to have access to the information necessary to read the territory, intended both as an artificial environment modified by the man and as a natural topography (conference held at the Instituto Superior Técnico in Lisbon, October 2018).

The data related to the history and culture of a place cannot be evaluated in themselves as objective data, but as elements to be connected, organized and processed within a more complex conceptual framework, which is what determines and distinguishes a vision from a simple idea.