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Geophysical site investigations have been performed in association with deployment of a dense array of 95 3-component
 seismometers on the Cavola landslide in the Northern Apennines. The aim of the array is to study propagation
 of seismic waves in the heterogeneous medium through comparison of observation and modelling. The small-aperture
 array (130 m×56 m) operated continuously for three months in 2004. Cavola landslide consists of a clay body
 sliding over mudstone-shale basement, and has a record of historical activity, including destruction of a small village
 in 1960. The site investigations include down-hole logging of P- and S-wave travel times at a new borehole drilled
 within the array, two seismic refraction lines with both P-wave profiling and surface-wave analyses, geo-electrical
 profiles and seismic noise measurements. From the different approaches a consistent picture of the depths and seismic
 velocities for the landslide has emerged. Their estimates agree with resonance frequencies of seismic noise, and
 also with the logged depths to basement of 25 m at a new borehole and of 44 m at a pre-existing borehole. Velocities
 for S waves increase with depth, from 230 m/s at the surface to 625 m/s in basement immediately below the landslide.