Former Newport Gwent Dragons flanker Richard Parks tackles the summit of Mount Everest today.
The four-times capped Welsh international is in the middle of a seven month pioneering race, entitiled the 737 Challenge, to reach the highest peak on all seven continents and the North and South Poles.
Parks made 30 appearances for the Dragons during a two-year spell at Rodney Parade before a shoulder injury cut short his career.
Parks aims to raise £1million for Marie Curie Cancer Care and has already completed the first six legs of his challenge.
Leg 1: The South Pole – on 27 December 2010, Parks successfully reaches the Geographical South Pole at 6.10am UK time.
Leg 2: Mount Vinson – on 8 January 2011, Parks successfully reaches the summit.
Leg 3: Aconcagua – on 5 February 2011, Parks successfully reaches the summit 5.54pm UK time.
Leg 4: Kilimanjaro – on 27 February 2011, Parks successfully reaches the summit at 4.57am UK time.
Leg 5: Carstensz Pyramid – on 15 March 2011, Parks successfully reaches the summit at 11.28pm UK time.
Leg 6: The North Pole – 11 April 2011, Parks successfully reaches the geographical North Pole at 2.20pm UK time.
His attempt to reach the roof of the world has been delayed by poor weather but he is set to conquer his biggest challenge yet.
Parks and Olympic rowing gold medalist Steve Williams will today scale the Lhotse Face, a 3,700ft wall of glacial blue ice, to reach the fourth camp en route to the top of the world’s highest peak.
"I am pretty tired to be honest, physically I feel like I am running up an escalator the wrong way at the moment, but I am also in not bad shape," said Parks.
A spokeswoman for the 737 Challenge said: "Should weather conditions continue as planned Richard and Steve would be due to summit on Tuesday."
Following Everest, next up for Parks is Mount McKinley, the highest mountain in North America, and Elbrus, which is the highest point in the Russian Caucasus.