The rural landscape of Molise is described by three materials: stone, brick and clay. Thick load-bearing walls catch the light, the sun and the heat to achieve rural buildings in accordance with the local tradition. Everything is made of poor materials, but, nevertheless, it is a system where environment and human presence are kept in balance. In a simple and natural way, landscape represents a super-system and thick walls a subsystem bioclimatic oriented to the exploitation of environmental resources, both material and energetic. Today, this building could be called sustainable and eco-friendly. Stone, brick and clay with straw materialize certain masonry types, characterized by wall thickness, considerably higher than those dictated by static requirements. The study of masonry types is developed up to the definition of the physical parameters that describe the thermal behavior of the wall. It gives us the chance to take a step towards a sustainable recovering.