Ordinarily, there are three demanding days on your 12-day itinerary. The first hardest day is a trek from Pheriche to Namche Bazaar consisting of a long steep walk from the Hillary suspension bridge all the way to Namche. The second hardest part is while trekking from Dingboche to Gorakshep while the third hardest part of the entire trek is the Kala Patthar climb at 5,545 meters / 18,192 feet and reaching to the base camp and back.