THE INCA' S BRIDGE.

The Inca's Bridge is a natural arch that form a bridge over the Cows' River, a tributary of the Mendoza River, in Mendoza Province, Argentina, near a place named "The Caverns." It is situated at 2,740m/8,990 ft above sea level. The area has a cold semi-arid climate, with moderate summers and snowy winters.
The Mendoza River is formed in the Andes Range between the Acon-Cagua and the Tupun-Gato Mountains, by the confluence of the Cows' River, the Caverns' River, and the Tupin-Gato River, the last being its major tributary.
The Upper Valley of Mendoza begins at around 2,600m/8,500ft above mean sea level, and it is U-shaped, of Glacial origin. The Mendoza River reaches Uspa-Llata, village situated in a scenic location on the road which crosses the Andes between Mendoza, in Argentina, and Santiago, in Chile ; then crosses the Pre-Cordillera through the settlement of Pot-Rerillos (1,380m above mean sea level); then flows along the Ca-Che-Uta Canyon and reaches the Plain. It forms an Arc and turns North East, finally emptying into the place named "Baths of Guana-Cache, which join the Saint John River, part of the system of the Desaguadero River. The Desaguadero River marked the traditional boundary between the Vice-royalties of Peru and Buenos Aires, Argentina.
The interaction of extreme elements like ice and hot springs was involved in the origin of the formation. In ancient times  ice covered the Mendoza River and acted as support for avalanches of snow, dust and rocks. So the dust over the ice on top of the River served as a path for the sulfurous water and petrified the surface, so when the snow melted, the Bridge remained by itself.
This area of the Andes is known for many Hot Springs. In the hayday of the Argentina's boom in 1904 the spa at Ca-Che-Uta was developed on a massive scale. Financed by the issue of shares to "speculative investors," a very substantial and luxurious hotel was built on the hill side above the River, with a bathing establishment below consisting of a large space lit from roof lanterns with individual bathrooms leading off it.  The establishment achieved a "particular success" through its link with the Trans-Andine Railway, which opened in 1910. The line straight passed the Hotel, and a special railway station was erected there. Passengers alighting on the platform at the spa would descend a staircase directly into the spa hotel, while their luggage would be brought down in a lift constructed within a tower modeled on a Italian campanile. Special packages and excursions were offered, and a wide range of glittering special events were celebrated in the local press. In 1934 a Glacial Flood in the Canyon completely destroyed the spa. The establishment never recovered. In 1986 a new less ambitious project was taken forward. Within the ruins of the original buildings a new smaller hotel was constructed. While the railway was abandoned in 1984, the spa is no longer in route to other destinations. Foreign tourism is less noticeable.
In March 1835, Charles Darwin (12 February 1809-19 April 1882) visited the Inca's Bridge site, and made some drawings with large stalactites.
The area is located between the two trail-heads for climbing the Acon-Cagua. The abandoned railway station has been turned into a Mountaineering Museum to display the cultural history of the area. It is open during the summer and is run by the founding group of friends.