The fortifications of Larrun from the late modern period are a series of military works situated on the mountain of Larrun, immediately to the west of the border between Spain and France. Some of the structures were erected during the 1793-1794 campaign and repurposed to impede the advance of the Anglo-Hispano-Portuguese coalition troops, which the future Duke of Wellington led. More than twenty redoubts are distributed across the territories of Ascain, Sare, and Urrugne, with partial coverage also extending to those of Saint-Pée-sur-Nivelle and Biriatou.
The battles of the late 18th century were primarily concentrated in the commune of Urrugne. The revolutionary forces were deployed in the Louis XIV, Bertuste, Bayonet, and Emigrés redoubts, situated along the border and overlooking the Bidassoa River as well as the route from Vera de Bidassoa. This configuration proved effective in containing the advance of the Spanish attackers. Théophile de La Tour d'Auvergne, renowned as the "first grenadier of the Republic," distinguished himself notably during these confrontations.
The circumstances at the outset of the nineteenth century were markedly distinct. Wellington advanced as a conqueror and successfully breached the Sare lock, subsequently attacking the slopes of Larrun before heading toward Bayonne. The French army, under the command of Marshal Soult, demonstrated valor in their defense of the Zuhalmendi, Grenada, and Madeleine Chapel redoubts. The inadequacy of the defensive position, ill-suited to counterattacks, and the inexperience of the defenders at the Ermitebaïta and Mendibidea redoubts permitted the Anglo-Hispano-Portuguese coalition troops to breach the defensive line and ultimately force the French forces to retreat towards Saint-Pée-sur-Nivelle.
The redoubts, situated on elevated terrain, were constructed by two principal architectural designs, tailored to the local topography. Examples of star-shaped redoubts include the Santa Barbara, the so-called "BF 29" (Border Marker 29), and the Bayonet redoubts. Others adopt a fairly regular quadrilateral configuration, exemplified by the Madeleine Chapel redoubt, or a pentagonal shape, as observed in the Emigrés and Olhain Chapel redoubts. A third category encompasses less common shapes, such as the ovoid Louis XIV redoubt in Sare, which is presumed to be a reuse of a protohistoric structure. Thirteen of these fortifications have been designated as historical monuments.
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