The trail to Kala Pattar, and then over the Cho La pass and up to Gokyo Peak is the most magnificent trek on earth. It's also the most breathtaking hike in Nepal.I walked it twice, in the fall of 1994,and again in the spring of 1998. Each time a 15 days round trip from Lukla with it's landing strip. The trek took me three time higher then 5500 meters above sea level. Not much oxygen, but a lot of fun.