Valle lies in the middle of Setesdal, a valley and a traditional district in Aust-Agder that included the municipalities of Bykle, Valle, Bygland, Iveland, and Evje og Hornnes. The Otra river flows from the Hardangervidda plateau in Telemark to the north, through the valley of Setesdal (and through Valle), into the sea near the Kristiansand.
Valle is separated from the neighbouring valleys in the east and west by large mountain plateaus. Before the valley was linked by road to Kristiansand in the 1840s, people routinely traveled east and west across these moorlands. The highest point is the Skammefjell at 1418 m. Waterfalls include the Hallandsfossen and the Gloppefossen.
There are two central population areas in the municipality, Valle and Rysstad, with the administration of the municipality located in Valle. These were originally in two separate municipalities (Rysstad was part of Hylestad municipality), but Hylestad and Valle were combined in 1962.
The Byklestigen pass is a torturous trail up a steep cliff face. Until the 1870s it was the only route to travel from Valle the middle Setesdal valley to Bykle in the north. It runs above the river Otra and was the site of numerous accidents on the hazardous route. Bykle was split off from the older municipality of Valle in 1903.
Between Valle in Setesdal on the western side of the mountains and Fyresdal on the eastern side, one finds a medieval track over the high plateau that priests and bishops used to get between the counties of Agder and Telemark. This track is named Bispevegen ("Bishop's Road") and every year a march called "Bispevegmarsjen" ("The Bishop's Road March") starts at Kleivgrend in Fyresdal.
Old silver smithies and barns can be seen in Rysstad. Traditional music is popular in this region, and there is a Jew's harp monument in the town.