Cuesta de Miranda

RN 40 follows the Río Miranda into the deep canyon between the Famatina and Sañogasta ranges, then climbs a rebuilt, fully paved corniche to Bordo Atravesado at 2,040 m and drops to Los Tambillos on the Villa Unión side.

From the Sañogasta turn-off, RN 40 heads west past the village of Miranda, at about 1,475 m, and follows the Río Miranda through a valley where green scrub and cardón cactus stand out against red, ochre and orange ground. Beyond the ravine of La Pelea, where troops dug in during a battle in 1867, the road climbs the cuesta on a corniche to Bordo Atravesado, at 2,040 m the highest point. The original gravel road, built by the Italian engineer Francisco Bolloli between 1918 and 1928, had 320 bends and was barely wider than one lane; between 2011 and 2015 it was realigned, widened to 6.7 m and paved, with a third lane for slow traffic on some climbs, steel guard rails and rockfall netting. Two stretches of the old road survive for walking or cycling, one beside the Mirador Cuesta de Miranda near the top. From the summit the southern side descends on gentler gradients to the hamlet of Los Tambillos. Condors are often seen overhead, and the speed limit is mostly 30 km/h.