Conversation so far:
How many peaks did Edmund Hillary climb after Everest?
Edmund Hillary climbed ten other peaks in the Himalayas on further visits.
What years was Edmund Hillary's climbing of other Himalayan peaks besides Everest in?
Edmund Hillary climbed ten other peaks in the Himalayas on further visits in 1956, 1960–1961, and 1963–1965.
What other accomplishment did Edmund Hillary acheive besides climbing Everest and other Himalayan peaks?
Edmund Hillary also reached the South Pole as part of the Commonwealth Trans-Antarctic Expedition.
What section did Edmund Hillary lead to the South Pole?
Edmund Hillary led the New Zealand section, on 4 January 1958.

Question: What was so unique about this trip?
Self-contained rewrite: What was so unique about Edmund Hillary's Commonwealth Trans-Antarctic Expedition trip?