The Puente del Inca is a bridge made by water and rock, and coloured by minerals. Over thousands of years, hot springs and the Las Cuevas river have deposited layers of orange, yellow and white sulphurous crust that formed a natural arch across the gorge, some fifty metres across. It stands in the high Andes of Mendoza province, at roughly 2,700 metres, on the main road between Argentina and Chile, and it was once part of the old trade route over the mountains.
The name suggests the Incas, but the bridge is natural. Travellers across the centuries have stopped to look at it and to bathe in the warm springs below, and in the early twentieth century, a spa hotel was built beside it. An avalanche destroyed the hotel in 1965, and the ruins still stand, rust-red and eerie. A row of stalls sells minerals, souvenirs and snacks, and the sulphur smell hangs in the air.
Above the village, the great peak of Aconcagua, at 6,961 metres the highest mountain outside Asia, comes into view when the weather is clear, and a short side road leads to the Horcones lagoon and the park entrance for climbers. The surrounding peaks are bare, brown and red, with patches of snow and glaciers, and the sky is a deep blue.
The riding is some of the best in South America. Route 7 from Mendoza climbs along the Mendoza river through Uspallata, then up to Puente del Inca and on to Las Cuevas, where it enters the long tunnel to Chile, with the Los Caracoles hairpins on the Chilean side as the famous final descent. The road is paved and well maintained, but trucks are common, the border area can have queues, and snow can close the pass in winter. The altitude can cause headaches, so take your time.
Fuel is the thing to watch. Fill up in Uspallata, about seventy kilometres below, and do not rely on getting any in the village. Basic food and hot drinks are available at the stalls and small restaurants. Summer, from December to March, is the best time to visit, though winter brings skiing at nearby Los Penitentes. The sun is strong, and the wind can be fierce.