Flat high-elevation surfaces in the Pyrenees are defined by thick weathered horizons that were developed from granitic lithology. We analysed such horizons in detail within two areas: the Bordères–Louron granite and the Aston massif. They are characterized by a lower fissured zone overlain by unconsolidated saprolite. Mapping these horizons allows a 3D reconstruction of the ancient palaeosurface with an elevation uncertainty of 50m. We discuss the age of weathering by means of stratigraphy and low-temperature thermochronology. The surfaces are clearly postorogenic, postdating Eocene–Oligocene denudation. Their incision and the fact they are stepped suggest (1) an increase of the local relief and (2) recent normal faulting.