Mt Chacaltaya (5420m / 17,785ft) used to be famous for being the worlds highest ski resort. In the 1940s the mountainside below the 2 peaks just left of centre in the image was mostly covered in ice. The glacier has receded rapidly since especially the early 1980s and there is now hardly any permanent ice left. The rapid expansion of the nearby cities of La Paz and El Alto may well have played a part as well as global climate change.