A GPS-derived velocity field from a dense geodetic network established in  the broader area of Athens is presented, whereas local variations of strain  rates across a major inactive tectonic boundary separating metamorphic  and non-metamorphic geotectonic units are also highlighted. An apparent differentiation of the eastern part of Athens plain with negligible deformation  rates, from the western part where relatively higher strain rates are  observed, indicate its control of the above mentioned boundary on the  contemporary deformation field of the region. These findings are in  agreement with previous geological observations, however, due to the dense local GPS network it was fatherly possible to localize and quantify the effect of such a major inherited tectonic feature on the deformation pattern of the area.