The Everest Base Camp Trek is the most famous mountain trip in Nepal. It is a 12-day round trip from Kathmandu to Kathmandu, which starts with a short scenic mountain flight to Lukla and treks to the base camp and Kala Patthar in 8 days including 2 rest days for altitude practice. After visiting the base camp and Kala Patthar, the trip returns back to Lukla in 3 days and fly out to Kathmandu.