The Hvannalindir area is an oasis of vegetation 640 m above sea level north of the Lindahraun lava field, sheltered by Mts Lindafjoll and the Krepputunguhraun lava field to the west and Ridge Kreppuhryggur to the east. In the Hvannalindir area, River Linda joins the River Lindakvisl, flowing from the southwest, where it branches out between vegetated banks past the freestanding crater Lindakeilir.

The name Hvannalindir is derived from the plant angelica, which thrives in the area undisturbed by the grazing livestock. It is an oasis and a unique ecosystem surrounded by deserts in all directions. The most conspicuous plants are willow and angelica at the edge of the lava and along rivulets, where the abundance is greatest. Only 32 species of flowering plants exist in the area. A total of thirty species of birds have been observed in Hvannalindir and near ponds south of the area. Six species can be considered annual nesting birds in the area: Pink-footed geese, long-tailed ducks, ptarmigans, purple sandpipers, red-necked phalaropes and snow buntings. The Iceland Nature Conservation Council (nowadays the Nature Conservation Agency) declared the Hvannalindir area inviolate in 1973.

Important cultural relics are preserved in the Hvannalindir area, including the ruins of an outlaws' lair, by the edge of the Lindahraun lava field. The ruins were discovered in 1880 by Thorgils gjallandi and three local companions, and were investigated by archaeologist Kristjan Eldjarn (later President of Iceland) in the summer of 1941. It is widely believed, that the legendary outlaw Mountain-Eyvindur and his consort Halla lived in the Hvannalindir area for some years after 1767 before moving to Eyvindarver near River Thjorsa further west in the interior.