The physiography of the Pallars natural region includes the Noguera Pallaresa river basin with its tributaries.

The region encompasses as well as the mountain ranges spanning the Pyrenees and Pre-Pyrenees area that surround the basin until the Serra del Montsec which forms the limit of the Pallars at its southern end.

[1][2] In present times the most important town of the Pallars is Tremp.

Alins, Alt Àneu, Baix Pallars, Espot, Esterri d'Àneu, Esterri de Cardós, Farrera, La Guingueta d'Àneu, Lladorre, Llavorsí, Rialp, Soriguera, Sort, Tírvia and Vall de Cardós The County of Pallars was a county during the ninth and tenth centuries.

The historical Ribagorça territories administered by the Generalitat de Catalunya were added to the newly created Pallars Jussà comarca.