We are located on the sunny shelf of Triangia, an area that extends to the hydrographic right of the Mallero stream, a few kilometers from the town of Sondrio, at an average altitude of about 500 meters. 
Twelve elongated bumps, about ten meters high, from 100 to 450 meters long and from 20 to 60 meters wide, dominate this shelf, an area of approximately 35 hectares. 
The bumps also have a high degree of parallelism: the azimuths of their direction show very modest deviations from the average of 85° N. The result is a very special landscape! 
Although the mountainous slopes of the Valtellina abound both in mountainous shelves and in roches moutonées - smoothed and rounded rocks, the combination of structural and morphological elements that can be observed near Triangia is quite peculiar and perhaps unique! 
From a lithological point of view, the bumps are characterized by the prevalence of poorly foliated metamorphic rocks, while from a structural point of view the context is that of the Austroalpine Domain (Adriatic margin affected by Alpine metamorphism) in a position very close to the Insubric Line, which it runs with an East-West direction along the valley that separates the bumps from the village of Triangia. The original rocks underwent a marked ductile deformation which plastically thinned and stretched them (a process known in metamorphic petrology as transposition). In geologically more recent times, glacier modeling has acted which differentially eroded the bedrock, characterized by marked discontinuities, close together and almost perfectly parallel to the Insubric Line. The preferentially engraved bands would coincide with more erodible rocks due to their mineralogical nature or degree of fracturing. The result is unique and suggestive: we can observe large parallel bumps dominating the landscape!