Complex sentence: The Khumbu Icefall is an icefall at the head of the Khumbu Glacier and the foot of the Western Cwm, which lies at an altitude of on the Nepali slopes of Mount Everest, not far above Base Camp and southwest of the summit.
Split into simpler sentences: The Khumbu Icefall is an icefall at the head of the Khumbu Glacier and the foot of the Western Cwm. The icefall is found at on the Nepali slopes of Mount Everest not far above Base Camp and southwest of the summit.