In this fieldbook we describe the most significative Geological and petrochemical features of the Sila and Castagna Alpine tectonic Units, belonging to the Northern Sector of the Calabria-Peloritani Arc (CPA). The Sila Unit is the uppermost Alpine thrust nappe in the Northern Sector of the Arc. It consists of the three different Variscan metamorphic complexes of Gariglione, Mandatoriccio and Bocchigliero, respectively medium-high-, medium-low- and low-grade, and by the late-Variscan plutonites of the Sila Batholith. The Longobucco sequence represents the Mesozoic sedimentary cover. The Castagna Unit, underlying the Sila Unit, consists of a Variscan epi-meso-metamorphic basement intruded by late-Variscan plutonites, both re-equilibrated in Alpine time. The field-trip includes 13 stops: the first covers the Gariglione metamorphic complex; the stops from the second to the eighth are devoted to the Sila Batholith; the ninth shows the Mandatoriccio and the tenth the Bocchigliero metamorphic complexes; the eleventh and the twelfth ones show the Castagna metamorphic and plutonic basement; lastly in the thirteenth stop, some tectonic contacts and structures of the Northern Sector, of the Arc are shown in the Corace tectonic window