The Isturitz cave is divided into two parts: the Hall of Saint-Martin (or South Hall) and the Main Hall or Hall of Isturitz (or North Hall). At the beginning of the Mesolithic, the opening that faces the town of Saint-Martin-d’Arberoue is estimated to have been 15 and 20 m wide and about 10 m high, making it visible to humans at a distance.

The most common human remains from Isturitz are cranial vaults, which have been cut-marked and modified to create drinking cups ("coupelles"), dating from the Magdalenian (∼15 to 12,000 years BP).