In 1930, Norbert Casteret found five animal-shaped stones in the Alkerdi 1 Cave, and in 1933 he reported the discovery in a short and rather confusing article. In 1935, Julio Caro Baroja made the prints of the engravings, ordered by Jose Migel Barandiaran. In 1973, Ignacio Barandiaran thoroughly researched the local paintings, and described 22 images, in two groups; however, he could not find the two figures mentioned by Casteret (the bison and the back of a horse). Finally, another decorated sector was discovered by Diego Garat and Olivia Rivero in 2014, with 20 images, most of them bison; Two "lost" images of Casteret were also rediscovered.

Therefore, there are four sectors with cliff art:

• Sector A: at the end of the corridor to the left from the entrance of the cave, in a stalagmite, 30 meters from the mouth. There are 7 images: a bison, a horse, a deer, an unspecified animal, and 3 sets of lines.
• Sector B: In the corridor leading to sector A, on the left wall. An animal, an indeterminate animal.
• Sector C: on the wall opposite the cave entrance, 15 meters from the mouth. Two animals, the wolf, and the female deer according to Ignacio Barandiaran.
• Sector D (Bison Gallery): go to the right from the lobby, and enter a corridor that starts from the left wall; in the last part a person just enters. There are 19 engravings: 10 bison, 3 horses, 4 unspecified animals, and 2 sets of lines; there is also a red spot.

Engravings from the Lower Madeleine period have been detected in the cave of Alkerdi (or Alkerdi 1), from 13,500 to 13,000 years ago.