Tuc d'Aubàs, Mountain summit between Bossòst and Bagnères-de-Luchon, Spain and France

Tuc d'Aubàs is a 2,073-metre mountain summit in the Pyrenees, on the border between Bossòst in the Vall d'Aran and France. The Catalan name Tuc d'Aubars appears in the source, while the French form is Pic d'Aubas. Its slopes rise above the Aran valley, and the summit marks the Spanish-French boundary line.

The mountain served as a natural boundary marker between France and Spain for centuries, with border stones placed at its peak. These markers reflect the long process of establishing and confirming the border between the two nations through the centuries.

The summit lies between Bossòst, in the Vall d'Aran, and French territory, so the mountain itself is the border point rather than a cultural crossroads. Bossòst, the nearest Aranese village, keeps Aranese, an Occitan dialect, as its own language alongside Catalan and Spanish. The name Aubàs/Aubars is the local toponym recorded for the peak.

The summit can be reached via a hiking trail from Portillon covering roughly 10 kilometers with an ascent of about 900 meters taking around five hours. Two mountain shelters at Col de Barèges provide rest and overnight facilities during the climb.

The summit lies on the watershed between the Vall d'Aran and France, and the Catalan name Tuc d'Aubars is used on the Aranese side while French maps write Pic d'Aubas. The 2,073-metre figure appears in Catalan sources for the mountain shared by Bossòst and the French side.