Fastest time to climb the top five 8,000ers without supplementary oxygen

Basque brothers Alberto (Spain, b. 3 November 1968) and Félix Iñurrategi (Spain, 1 April 1967 - 28 July 2000) set the record for the fastest time to climb the top five 8,000ers, taking 4 years 219 days to climb Makalu, Everest, K2, Lhotse and Kangchenjunga between 30 September 1991 and 6 May 1996. Significantly, they did these climbs without the use of supplementary (bottled) oxygen. The five highest 8,000ers are considered significant because the difference in height between the peaks is greatest between the 5th and 6th mountains, with 284 m (931 ft) between Makalu and Cho Oyu.