A 160km altiplano ride from La Paz across the Bolivian high plateau to the sacred lakeside town of Copacabana. Climb out of La Paz to the El Alto rim at 4,061m, cross 100km of altiplano with the snow-capped Cordillera Real to your right, then board a wooden barge across the 850m-wide Strait of Tiquina (vehicles ride separately from passengers — Bolivia at its most authentic).
Clone it to your planner, customize dates and stops, then ride. All free.