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We use passive seismic methods to obtain a model of the seismic-velocity structure of Campo de Dalías, a large (~ 300 km2) coastal plain in the southeastern mountain front of the Betic Cordillera (SE Spain). To this aim, H/V spectral ratios of ambient noise were computed from broadband records at 310 sites, approximately on the vertexes of a 1000 x 1000 m square grid. Two approaches based on power spectral densities and the Hilbert-Huang transform have been compared. Most of the H/V ratios show clear peaks in a wide frequency range (down to~ 0.25 Hz) associated with up to~ 1000 meters of soft sedimentary rocks (mainly Miocene marls) overlying the stiffer basement. Broader peaks appear in the foothills of Sierra de Gádor mountains. The spectral ratios were inverted in the range 0.15–15 Hz to obtain horizontal layered models of the local structure from which a 3D model was interpolated. Forward …