Also known as Vinicunca, the Rainbow Mountain is a viral hit with travelers thanks to the photogenic nature of its mineral stripes. Getting there requires good physical fitness and proper acclimatization. The 10km round-trip to a high viewpoint facing the mountain is gentle in grade but the high altitude (reaching above 5000m) takes its toll. Try to ascend slowly. With great Ausangate views.
Be prepared to be one of hundreds hiking the trail – you will find no solitude here. Tour buses from Cuzco go for cheap, but consider whether you want to be herded up the mountain in a large group. Ask other travelers about their experience and look for agencies that offer trips with smaller groups and pay more attention to client needs. Some offer overnights in basic family lodgings nearby. The main access is via Pitumarca, which is a three-hour drive from Cuzco, ending with an hour on a very steep road with sheer drops. A newer alternate access is being developed through Cusipata, on the other side of the mountain, with only an 8km hike that starts at a higher altitude, though infrastructure is more developed on the other side.
Bring plenty of water, wear hiking clothes and bring extra layers. There are small stands along the way selling tea, water and snacks. Horses can be rented (ascent/descent S60/30), led by locals. Nearby Red Valley (S10, two checkpoints) is worth the side trip if you have the time.