Even to the huge bummer that is glacial melting, there are bright sides: The radiant colors of Vinicunca (aka Rainbow Mountain) might have gone unseen had rising temps not melted the peak"s glacial caps beginning in the 1990s. Rainbow Mountain"s streaky sediment layers, multicolored like a wildflower bloom, were revealed by the 2010s. Since then, it"s become the most visited natural attraction in the lofty Peruvian Andes of the Cusco region. At more than 17,000 feet above sea level, Rainbow Mountain isn’t the tallest peak in the area—towering Ausangate is nearly 21,000 feet in elevation—but most visitors will need time to acclimatize before attempting the trek to the summit.