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This entity includes the Chonas Plain and the small Amballan Plateau. The latter, at an elevation of over 300m (1000 ft), overlooks the Rhône by 150m and the Chonas Plain by 100m. The Varèze Valley marks the southern edge of this landscape.

This broad flat plain is covered in loess and Würm silt and is used for cropland, while isolated dwellings and a few lone trees can be seen on the horizon.

The railway line follows the Rhône between Vienne and Chanos, but the N 7 and the A 7 motorway leave it right at Vaugris to take a shortcut through the Chonas Plain and the Louze Plateau. These roads cut through the middle of the plain but have not spurred any commercial build-up.

The small Vienne-Reventin airport is nestled between A 7 and N 7.

The flat, undistinguished plain, which is surrounded on the northwest by the slopes of the Amballan Plateau and on the northeast by those of the Bonnevaux Plateau is the site of large-scale intensive cereal-growing, with only the occasional tree and even fewer hedges. It is hard to see a motif that would invite interest, all the more so as the roads have sometimes disappeared due to sales and land consolidation or after simply being abandoned. The result has often been landscapes that could be described as open, but in reality are closed to exploration, which conflicts with the very idea of a landscape and is the source of numerous abuses, such as illegal dumping. The selling off and abandoning of the land took place more frequently between 1945 and 1980 than today. This undermined the continuity of the road network, which is essential for traversing the area. The way urbanism documents were drawn up also reveals negligence, as they did not always take into account the importance of preserving the network of communal and inter-communal roads and lanes.

The contrast with the plateaus and the hills that surround them like an amphitheatre is all the more striking has they have preserved semblances of a bocage, with occasional meadows and woodlands. As for the rest, it has been taken over by widespread diffuse urbanisation, leaving few visible village skylines. One result of this type of organisation, which has been fuelled by the proximity of Vienne and the commercial areas of the Rhône Valley, is to erase the interesting features of the landscape. One expression occasionally used to characterise this process is that it drowns features of local interest in an undifferentiated layer that has no rationale other than to comply with requirements for distances between construction projects. But plateaus do not have that many noteworthy motifs in the first place. This is all the more reason to preserve whatever they do have, and there is no plateau so flat that it has nothing of interest, as can be seen in those in Champagnier and Matheysine .

Only the gently undulating upper part of the Amballan plateau still stands out for its sweeping panoramas westwards.