Since ancient times, the Phlegraean Fields were one of the most popular travel destinations. For the particular geological characteristics of the territory, the nobility of ancient Rome built numerous pleasure villas, especially in the area between Pozzuoli, Baia and Bacoli, and later, in the modern and contemporary age, the travellers of the Grand Tour made the Phlegraean fields a real centre of tourism known all over the world. Over the centuries, through their travels, local and foreign scholars described the environment of the Phlegraean fields in their travel notebooks, often accompanied by sketches and drawings. In addition to these precious proofs, of particular interest are the articles published in the architecture and engineering periodicals within which projects of buildings are reported to be placed along the coastal strip, changing its original appearance. Through the analysis of bibliographic, documentary and iconographic sources, such as the guides of monsignor Pompeo Sarnelli, “La Guida de’ forestieri, curiosi di vedere, e di riconoscere le cose più memorabili di Pozzuoli, Baja, Cuma, Miseno, Gaeta. Ed altri luoghi circonvicini”, and canon Andrea de Jorio, “Guida di Pozzuoli e contorno”, the drawings of the French architect Prosper Barbot and the periodical “Bollettino del Collegio degli Ingegneri e Architetti in Napoli”, this paper intends to illustrate the environment of the Phlegraean fields during the XVIII and XIX centuries, making a comparison with the environment of the contemporary urban context. From the comparison of the sources it emerged how the image of the Phlegrean landscape has rapidly changed over the centuries. Today, most of the archaeological monuments and the same coastline are covered by a poor quality contemporary building, the result of the lack of control of the institutions, and which today gives the image of an environment of great but disordered beauty.