The earthen architecture widely spread in many countries of Europe, America, Asia, Africa, testifies to a particular material and immaterial culture. Nevertheless, it is a fragile heritage, which needs continuous maintenance. To encourage the preservation of such evidence of building techniques, an experimental campaign aimed at the development and evaluation of the performances of protective earthen plasters was undertaken. The durability of the plasters was improved through the addition of different additives, some of them traditional (such as lime and gypsum) and others innovative (geopolymers, enzymes), and resulting from industrial wastes (cement kiln dust). These additives have been selected considering low production costs and a reduced environmental impact, to improve the sustainability of the interventions. The performances of the earthen plasters in terms of efficacy (resistance to water erosion, water absorption, drilling, thermo-hygrometric cycles) and compatibility (changes in color and water vapor permeability) have been evaluated. Good performances were obtained by the different mixtures and, in particular, by those stabilized with gypsum. The results of this experimentation could find a useful application in the preservation of both ancient and new earthen built heritage.

Earthen architecture, by its nature, is a fragile because it has a poor resistance toward the action of weathering, which has also increased in recent years through the effects of climate change. The presence of interesting examples of earthen brick buildings, for example, in the Piedmont Region of Italy, is characterised by the absence of rendering, which reveals the need to test treatments for the protection and/or strengthening of the walls of these buildings. This action is of fundamental importance to improve its resistance to the aggressive action of atmospheric agents and avoid their disappearance. A testing campaign adopting protective products with sustainability characteristics and low environmental impact was carried out on earthen brick walls. Different products belonging to various categories (synthetic polymers, natural resins, nano-structured materials) and selected based on previous experiments or tested for the first time on earthen surfaces were selected. The performance assessment of the products was carried out by taking into account the standardised procedures in the field of cultural heritage conservation through the following tests: water absorption, water vapour permeability, drilling resistance, water erosion tests (Geelong and spray), contact angle measurements, colorimetric measurements, and ageing tests. Although the choice of the optimal protective product should be made on a case-by-case basis, where it is not sustainable to proceed in this way, the results of this experimental campaign—in the presence of materials and weathering conditions similar to those of the case study analysed—will provide indications in identifying of the most appropriate product.

The landscape of an area is not only made up of natural elements but also of man-made elements represented by civil and agricultural artefacts and much more. These elements used to blend aesthetically and harmoniously with the landscape itself thanks to the use of local building materials. Particularly, this contribution examines the use of the travertine in the architecture of the Tuscany region from the Etruscan time to the contemporary age. In Tuscany, travertine is a remarkable example of an identity stone of the territory, so rich in thermal springs that favoured the formation of large deposits of this stone widely used in public and private buildings both in interior design and urban furnishing. The work was carried out through a survey in the Tuscan territory and collection of bibliographic information on the architectural web sites. The survey made it possible to collect a photographic documentation and to assess the state of conservation through the empirical observation of the morphologies of decay when present. Indeed, this stone material in the Mediterranean climate, which characterises Tuscany, shows a good durability against atmospheric agents but may be affected by a chromatic alteration that tends to give the surfaces a greyish appearance. This aesthetic issue is more evident in the Tuscan travertine due to is classic whitish colour.

Over the years, people’s interest in protecting the natural environment and its resources has increased significantly. In this context, natural parks have become a new tourist destination, which has grown exponentially in recent decades and developed into mass tourism. This made it necessary to realize adequate infrastructures (roads, accommodation facilities reception, etc.) to allow visitors to enjoy parks. A recent trip to China made it possible to observe how this type of tourism has developed and raised some concerns and the need to understand whether this phenomenon is also present in other countries. In particular, this research examines the infrastructures (roads, accommodation facilities, and visitor centres) of some parks in the United States and Europe to compare them with the Chinese experience. The analysis revealed a difference in the visiting facilities of European parks compared to those in China and North America. In fact, the management and fruition of European parks seem to have less impact on the territories because they make use of road networks and accommodation facilities already present in the territory and that are often present in small villages. While in the case of China and the USA, it has been necessary to build new visitor centres and accommodation facilities in territories that were often uninhabited.

The research examines the alteration phenomena of Giglio island granite, a rock quarried by Romans from the 3rd century, used for columns in the Italian peninsula and later reemployed in many Christian religious buildings. The study has shown that already in the bedrock there are small percentages of clay minerals. Starting from this condition, the alteration develops by an increase in porosity, which in turn favours the establishment of a slight hydrolysis of the silicates with a decrease in Na, Ca, and K, in accordance with the sericitisation process. The alteration proceeds with a further increase in porosity, apparently not related to a real loss of cohesion, which, however, occurs shortly after, highlighting the necessity of a continuous monitoring of the state of conservation of the material in the architectural heritage.