Grez-Doiceau The commune of Grez-Doiceau is comparatively large, covering some 5,544 hectares (ie 13,700 acres). Its undulating countryside provides a wide variety of landscapes and scenery. The valley of the River Dyle and its main tributaries (the Pisselet, the Train and the Nethen) forms the hydrographical structure of Grez-Doiceau. The alluvial valley-floors are flat, whilst their carved sides are steep. Wide plateaux separate the different valleys. A considerable amount (58 per cent) of the land in Grez-Doiceau is agricultural, mainly on the plateaux and the alluvial valley-floors. Wooded areas, also of considerable extent (20 per cent), are mostly located on the hillsides. The population of Grez-Doiceau, currently above 12,000, has been growing rapidly over the last three decades. Since the last merging of municipalities, Grez-Doiceau includes the following villages: Archenne, Biez, Bossut, Cocrou, Doiceau, Gastuche, Gottechain, Grez, Hèze, Nethen en Pécrot.