Sassopiatto e Sassolungo

3D model from digital elevation data (DTM) by Province of Bolzano 2.5x2.5m (CC0 license http://dati.retecivica.bz.it/it/dataset/modello-digitale-del-terreno-dtm-25-x-25m ).

GeoTIFF to STL using https://github.com/anoved/phstl
Faces reduction using Meshlab
Blender for extrusion and cutting