The Isturitz and Oxocelhaya caves (French: Grottes d'Isturitz et d'Oxocelhaya) are an important Paleolithic site where a Neanderthal mandible was found, as well as later modern human finds associated with the Aurignacian, Solutrean and Magdalenian.

[1] The caves are located in the Gaztelu hill in the Arberoue Valley in the foothills of Pyrenees, in Lower Navarre, a traditional region of the department of Pyrénées-Atlantiques, southwestern France, part of the French Basque Country.

They form part of a system of three caves carved into the limestone Gaztelu hill in succession by the Arbéroue stream, which flows into the Lihoury, a tributary of the Bidouze.

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 a distance.

[4] 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).