Château d'Etchaux, Medieval castle in Saint-Étienne-de-Baïgorry, France.

Château d'Etchaux is a castle with a rectangular plan, two round corner towers to the north-east and north-west, and two watchtowers to the south-east and south-west. Its walls are limestone and sandstone covered with plaster, and the main entrance to the north bears the inscription "IHS MARIE 1555" above the door. The building stands on a motte overlooking the village.

The castle was the seat of the viscounts of Baigorri from 1033 to 1832, with the oldest parts dating to the 12th century. Gratien d'Etxauz had the present building erected around 1555, and it was largely rebuilt at the end of the 16th century. The interior was rearranged in the 17th century, and the castle passed to the Caupenne d'Amou family in 1732. It was inscribed as a monument historique on 21 December 1989.

The castle was the seat of the viscounts of Baigorri, a family close to the kings of Navarre; Bertrand d'Etchauz, bishop of Bayonne from 1599, was its best-known son. Above the main north door, visitors can read the inscription "IHS MARIE 1555", linked to Gratien d'Etxauz, who had the present building erected around that year.

The castle now operates as a hotel and guesthouse, so visitors can stay in the restored rooms. The main entrance is on the north side, above which the inscription "IHS MARIE 1555" can be read. The building stands on a motte overlooking the village, and the climb is short but steep.

The north entrance door carries the inscription "IHS MARIE 1555", likely marking the rebuild ordered by Gratien d'Etxauz. Inside, a thick wall almost identical to the outer wall shows where two of the original four towers were demolished to enlarge the castle. The staircase railing is forged iron.