The paper deals with the settlement of tall buildings, supported by shallow foundations, in the City of Santos, Brazil. After describing the Geological History of the clayey sediments of Santos Coastal Plain, the paper presents briefly their Geotechnical Properties, emphasizing the pre-consolidation mechanisms and the 4 classes of soft marine clays. With this background it is shown that the soft clays of Santos City, deposited before 7.000 years BP, overlaid with a 8-12 m thick sand deposit, were submitted to dune action that may explain: a) the differences in settlements of buildings with the same height and thickness of soft layer, in some cases in a proportion of 1:3; and b) some occurrences of inclined buildings.