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Trièves is a large cirque with a mammilated or hummocky surface that was hollowed out of the black marl underlying the Tithonian limestone. It is drained by the Ebron and its tributaries, which have cut deeply into the soft rocks. This has created spectacular badlands-type erosion, with jagged land forms and sharp contrasts between the bare black rocks and the greens and yellows of the farmland.

The Tréminis cirque, the source of the Ebron, looks like a small cirque within a larger one. It forms a closed, wooded compartment, where the arable land amounts merely to a few plots on the valley floor. The Grenoble-Sisteron road and railway run along the western border of Trièves, but these arteries have not affected the otherwise normal development of the local economy, which is based in the main on agriculture.

The landscapes of Trièves have a distinct local colouring. Like the landscapes of Beaumont, they are marked by Mediterranean influence and stand out from all the other landscapes in Isère.

These local colours are due above all to the vegetation. The spruce and hornbeam trees have disappeared, to give way to common oaks and durmast oaks and field maples, which are replaced on the broad, bare slopes by box trees and large stands of junipers, Scots pine woodlands and occasionally even lavender, which is so characteristic of the French Midi.

Another distinctive feature is the general ambience of tranquil well-being that derives from a well-maintained and protected environment in the largest natural cirque in the department, bounded to the east by the Dévoluy Massif and to the west by the cliffs of the Vercors. Trièves was once the area's breadbasket and sheep producer, and was well known for its lambs. Agriculture has continued to thrive there and, with the arrival of dairy cattle and mechanisation, is the foundation of the economy.

Mens, with its labyrinth of narrow shady streets on the wooded valley floor, is typical of this agreeable environment. In contrast, the villages on the western side of the area, on the other side of the Ebron, are generally perched, also like in the French Midi, at the upper edge of a topography of natural vegetation, fields and pastureland. Saint-Michel-les-Portes is a perfect example. The village is tightly bunched around its church tower, on a small cultivated plateau, where it shows off its beautiful architecture, with its hip slate roofs, with Mont-Aiguille on the horizon.

Tréminis also deserves to be mentioned because of its perfect small cirque, closely surrounded on every side by steep wooded slopes. This area has drawn great attention, including from Giono, which it inspired, as well as perhaps Daudet as well, whose "little goat" would certainly have been fascinated by the two mountains of Obiou (2790m/9153ft) and Grand Ferrand (2759m/9052ft).

There are numerous villages along N 75, which crosses the west of the area looking out over the surrounding landscapes. It is thus a major feature itself of Trièves, which, like Matheysine is crossed by an itinerary that, though of national interest, is perhaps not very well known. One of the reasons for this may be that the road does not actually pass through the villages. Another reason, cultural in origin, is that the area has always been a north-south passageway, both for the seasonal migration of livestock (called "transhumance") and the age-old tradition of peddlers. The prospect of developing the N 75 thus provides an opportunity to display another dimension of the area, i.e., its east-west dimension, and the bridge that it forms between the Vercors and Ecrins massifs and their respective Parcs Naturels. This development should be viewed as an opportunity for an attentive mise en scène of the surrounding area and the departmental roads that cross it:

D 66: Lalley – Mens - Corps,

D 526: Clelles – Mens - La Mure –Valbonnais - Col d'Ornon - Le Bourg-d'Oisans,

D 7: Clelles – Chichilianne - Col de Menée,

D 216: Lalley – Le Château-Bas – Tréminis

D 34: Col du Fau – Mens.

Framing the views of the South Isère landscapes from the road raises the issue of the underlying dynamics and principles from three points of view: the landscape programs, which are to strengthen the legibility and distinctiveness of the riverside landscapes from the roads; the definition of the vocabulary and descriptions used for the itinerary; and the geometry and landscaping of the roads, in particular establishing from the outset the decisive role of the views of the landscapes traversed (Laverne, 1996: 56).