The aim of this Master’s thesis is the study of the history of the Old Port of Trieste with the main focus on the construction history of the area and the observation of the masterplans proposed over the course of many decades for its restoration and reintegration in the fabric of the city.The expansion of the city of Trieste is closely related to the foundation and construction of the port and should therefore not be over-looked, more so if one thinks that the first steps towards the modern development of the city as an emporium have been moved with the construction of the Teresian District - Borgo Teresiano - from 1736 onwards, following the proclamation in 1719 of the harbour of Trieste as a freeport. This district, which has been described by Giovanni Fusconi as a “Prothesis” of the monarchy towards the sea, is only a first example of the interest of the Habsburg for the city and their willingness to undertake great in-vestments to realise its potential.During the years preceding the opening of the Suez Canal, to prepare the port for the increase in trade favoured by the connection with the Levante, a project for the construction of a new port for the city was commissioned. With the work of the hired engineer Paulin Talabot and the subsequent reworking of his plans at the hand of the engineer H. Pascal, Trieste received a new huge port, located north of the city centre.This port, which had initially been fiercely opposed by the local population, gave the city its modern cityscape and became inseparably bound to its everyday life.After the description of this first project and its alternatives proposed by the local population, a new expansion of the Port and the related construction of the Joseph’s District - Borgo Giuseppino - will be observed.This succession of expansions and projects is an evidence of the economical livelihood of the city, which had been artificially developed by the monarchy from a village to one of the most important trade and financial centres of the time.This development has nonetheless not occurred without obstacles on its path, then because of the unfavourable characteristics of the seafloor in the bay of Trieste, the harbour had to be rebuilt many times during the XVIIIth and the XIXth century and then once again it had to be restored after the second World War.In spite of these problems, the New Port - today known as the “Old Port” - developed into the leading driving force of the city’s economy. Such was the importance of the port for the city and the monarchy, that it would be described as the main employer of Trieste and many enterprises had their headquarters and branch offices in it. Nonetheless, this concentration of capitals and workforces was also a consequence of the will of the Habsburgs to establish Trieste as the trading centre of the empire and was realised also through the technological experiments in the harbour for materials and constructions.In fact, it is possible to say that the port of Trieste was a testing ground for the construction industry and most importantly for the concrete industry. It was here that most of the European patents for this material were used, sometimes even before an official recognition as in the case of the “Einbetonierte Eisensäulen”, the usage of which had been proposed by the TU Wien. In this text the many enterprises active in the port will be listed, and the numerous patents used in the Lagerhäuser will be analysed, as for example the Patent Hennebique, the Patent Edmund Ast & Co., the Patent Wayss and the Patent of the engineers Geiringer & Vallon. To better understand the patents and their application it will be necessary to observe the buildings of the Old Port, which are subdivid-ed into Lagerhäuser – warehouses - and Hangars. Furthermore, these buildings will be subdivided into one-storeyed, two and three-storeyed, and four-storeyed warehouses, since they have been constructed with different techniques and can so better describe the development of technologies in the port.To further study the construction techniques and the structure of the one-storeyed ware-houses and hangars, the Hangar Vini, the wine hangar, will be analysed. Although this particu-lar building is situated outside of the Old Port, the construction techniques and materials used are the same of all the other one-storeyed warehouses located inside the Port.Similarly, the warehouse 26, the largest building in the port and one of Europe’s largest warehouses, will be taken as an example of piled foundations for the foundation’s works of many buildings in the harbour and as an example for the usage of the Melan patent, for the construction of vaults for lighter ceiling constructions with higher load carrying capacity. Successively, the warehouses 4 and 20 will be used as examples to describe the application of the Einbetonierte Eisensäulen, that repre-sented a technological advantage of Trieste against its competition of the time from the ports of the North Sea, mainly Hamburg. To conclude the chapter on the architectural history of the Port, the figure of the architect Giorgio Zaninovich will be remembered, who acted in the years between 1910 and 1914 as “Technical Director and Special Consultant for civil and structural engineering in the Port” for the technical office of the Magazzini Gen-erali. Although he had a very prolific produc-tion, many of the projects he supervised while invested of the role of Technical Director do not carry his name. Nonetheless, academics could assign at least three buildings to him: the monumentas access to the Old Port, the Workers’ House - also known as “Locanda” and the Transformers’ Station. Giorgio Zaninovich isn’t only important for his role as Technical Director of the Port, but also because of his endeavours as architect to harmonically integrate the characteristics of the contemporary architecture and of the European style currents - mainly the Viennese Secession - with the local architectural style and create an original and autochthonous In-terpretations of them. He laid the basis for the development of a Triestine undercurrent of the Industrial Style, which gained in his pro-jects, one building after the other, more and more originality, until its sudden interruption caused by the outbreak of the war. In the second half of this dissertation the main topic will be the masterplans for the revival of the Old Port of Trieste and their subdivision into two different categories: the masterplans completed before the publication of the protective measures for the existing buildings in the Port - e.g. Luciano Semerani, Nicolò Savarese, Stefano Boeri - and the masterplans published afterwards - e.g. Maurizio Bradaschia and Sir Norman Foster -. Consequently, it will be possible to understand the development of the architectural practice in the last decades in relation to the topic of maintenance and care of historic buildings and monuments, specifically the industrial ar-chaeology, and mainly how these protective measures for the buildings have been integrated in the projects.Subsequently, these masterplans will be compared with the current development plan for the Old Port from the year 2019, so to see which interventions from the projects of the previous decades have been integrated and in which direction is this area of the city going to develop.