Pre-Columbian Mountaineering

From Wikipedia page on World Altitude Records (mountaineering):

European exploration of the Himalaya began in earnest during the mid-19th century, and the earliest people known to have climbed in the range were surveyors of the Great Trigonometric Survey. During the 1850s and 1860s they climbed dozens of peaks of over 6,100 m (20,000 ft) and several of over 6,400 m (21,000 ft) in order to make observations, and it was during this period that claims to have ascended the highest point yet reached by man began to be made.

Most of these early claims have now been rendered redundant by the discovery of the bodies of three children at the 6,739 m (22,110 ft) summit of Llullaillaco in South America: Inca sacrifices dated to around AD 1500.  There is no direct evidence that the Incas reached higher points, but the discovery of the skeleton of a guanaco on the summit ridge of Aconcagua (6,962 m, 22,841 ft) suggests that they also climbed on that mountain, and the possibility of Pre-Columbian ascents of South America's highest peak cannot be ruled out.