A natural rock bridge in the Andes Mountains, formed by hot springs and mineral deposits. The golden-hued arch spans the Mendoza River at 2,720m altitude.
Puente del Inca, a village in Argentina’s Mendoza Province, centers around a large natural stone arch crossing the Las Cuevas River. This orange-brown bridge formed through glacial shifts and mineral-heavy hot springs, sitting 2,720 meters high at the foot of Aconcagua, the tallest mountain in the Americas. Walk through the remains of a 1920s thermal spa hotel destroyed by landslides, look at stalls with rocks covered in mineral crusts, or study old climbing equipment at the Museo del Andinista. Ice patches cling to areas near steaming water pools here, with the Andes creating a jagged backdrop. The site’s unstable ground means you view the bridge from a protected platform rather than walking across it.
How the Natural Bridge Formed
The 48-meter stone arch took shape over thousands of years as glaciers pushed debris into the valley. Hot springs carrying sulfur and iron seeped through this material, cementing it into solid rock while the river eroded softer layers beneath. Colors range from mustard yellow to rust red depending on mineral concentrations in different sections. Contrary to its name, no Inca builders worked here—geologists confirm natural origins, though stories say warriors created it by forming a human chain. View the bridge from the main observation deck, where you’ll notice icicles hanging from the base in winter and mineral drips creating bumpy textures. Guides point out how thermal waters still flow through cracks in the rock walls.
Hot Springs and Their Uses
Warm water emerges at 34°C (93°F) from springs below the bridge, long used by indigenous groups for health treatments. Early 20th-century visitors soaked in tubs at Hotel Puente del Inca until landslides buried parts of the building in 1965. Its surviving chapel now sits under mineral stains near the riverbank. Though bathing in the main springs isn’t allowed, watch how vendors submerge small items in side pools to grow colorful crusts—they sell these petrified trinkets at nearby stalls. The iron-rich waters also strengthen the bridge’s structure, acting like natural cement between rocks.
Access to Aconcagua and Hiking Routes
Most climbers heading to Aconcagua’s 6,960-meter summit pass through Puente del Inca. The old train station by the village entrance holds a museum with ice axes, torn tents from historic climbs, and maps of early expeditions. Three main trails start here: a 15-minute path to hot spring viewpoints, a 2-hour loop along the Horcones River, and a full-day hike to Confluencia base camp. Park rangers give free talks about how pre-Columbian traders crossed this area using natural rock paths. From December to February, you’ll meet international climbing teams stocking up on supplies before their ascent.
Getting There and Nearby Stops
Drive 180 kilometers west from Mendoza City on the main highway toward Chile, passing Uspallata Valley’s red rock formations and ancient storage ruins built by Inca travelers. Arrive before 10 AM to avoid midday crowds at the bridge viewing area. Between June and September, snow sometimes closes high sections of the road—check conditions if visiting then. Pay parking attendants directly at the site entrance; they accept cash only. Sleep in Uspallata for hotels with hot showers and steak restaurants, or stay in Las Cuevas for simple bunk beds near the Chile border. Budget an hour to see the bridge, museum, and shops before driving to Cristo Redentor statue or Los Penitentes ski slopes.
