The classic Inca Trail has a strict daily quota and sells out months ahead; it also closes for the whole of February for maintenance. The good news is that the alternatives are just as good and several are more spectacular.
Salkantay — four or five days
This is the most popular alternative. It rounds the Salkantay peak (6,271 m) over a pass at 4,630 metres and then drops into cloud forest, through coffee plantations and orchids, finishing at Aguas Calientes. The change of landscape is its great attraction. No special permit is needed, but you must be acclimatised: the second day is hard.
Choquequirao — four to nine days
Choquequirao is an Inca complex comparable in extent to Machu Picchu, still only partly excavated and almost empty of visitors, because the only way in is on foot. It takes two days down into the Apurímac canyon and up the other side, with fifteen hundred metres of descent and ascent each way. Demanding — and probably the closest thing left to reaching Inca ruins before tourism arrived.
Ausangate and Rainbow Mountain
The five-day Ausangate circuit is the highest and the most solitary: passes above 5,000 metres, lakes coloured by minerals, herds of alpacas and Quechua herding communities. Vinicunca, Rainbow Mountain, lies along the way, its stripes produced by different minerals in the sediments.
If you only want Vinicunca it can be done in a day from Cusco, but two things are worth knowing: you leave before dawn, and the viewpoint stands at 5,036 metres, an altitude at which unacclimatised visitors often suffer badly. Horses are available for the final stretch. The nearby Red Valley is usually almost empty.
Cordillera Blanca
Based in Huaraz, the Cordillera Blanca holds the highest tropical summits on the planet. Laguna 69 is a long day walk; the Santa Cruz circuit takes four days. Huascarán, at 6,768 metres, dominates the range.
Season and kit
May to September is the dry season in the highlands and the only sensible window for high-altitude trekking. From January to March it rains daily in the mountains and many passes become dangerous. Nights are cold even after sunny days, so bring a proper sleeping bag and layers; sun above four thousand metres burns far more than it appears to.