With the aim of enriching and innovating regional tourism and promoting new offerings based on two aspects that characterise the regions of Trás-os-Montes and Galicia, endogenous resources and thermal springs, this research has been launched, creating synergy between these two potentialities. Its main objective is to evaluate the contribution of incorporating thermal waters into the sustainable production of chestnut flour using chestnut by-products, shells and hedgehogs. This study involves obtaining more specific and concrete answers, such as demonstrating the viability of using chestnut by-products, shells and hedgehogs, in the production of chestnut flour. It is imperative to verify whether the introduction of chestnut by-products adds value to the nutritional characterisation of the product to be developed. The other variable under study is the introduction of thermal waters during the processing of the chestnut flour. These waters come from the thermal springs of Chaves, Portugal, and Ourense, Spain. Various chestnut formulations will be created with the different waters and by-products from the regions mentioned and then evaluated in terms of the chestnut flour's organoleptic, physical, chemical, and nutritional characteristics, as well as the effect of its consumption on human health. Once the most suitable formulation of sustainable chestnut flour with thermal water has been obtained, gastronomic experiments will be carried out with this new product to assess its degree of acceptance by consumers.