The city of Auch expands on either side of the river Gers. On the left bank, around the cathedral lays the medieval part, whereas on the right bank, 19th and 20th century buildings stand in the plain, on the side of large avenues opened to the exterior.
From whichever direction you arrive in to the capital of Gers, especially coming from Toulouse, 'Auch' presents you with a prestigious architectural ensemble made up of St Mary’s Cathedral, the monumental Staircase, the Prefecture (previously an archiepiscopal palace) and the Tower of Armagnac. Auch is built on and around a hill on the west bank of the Gers River, west of Toulouse. It is a farm market and commercial centre with a variety of manufactures and an important trade in Armagnac brandy, poultry, wine and grain.The interesting old town stands on a bluff overlooking the tree lined river, with the Cathedral Ste-Marie prominent at its edge. Although not finished until the latter part of the seventeenth century, the cathedral was built in basically late Gothic style, with a classical facade. The choir and the stained glass, both were begun in the early 1500s are of particular interest. The stalls show extraordinary virtuosity and detail. The eighteen windows, unusual in being a complete set, are equally rich in detail. They are the work of a Gascon painter, Arnaud de Moles.