Each year a famous sports personality, whose identity is kept secret until the night, lays a wreath on Guto’s grave. They then run to Mountain Ash carrying a flaming torch, supported by local athletes. Over the years many famous sporting personalities have had this honour - Ann Packer (Brightwell), Ron Jones, Lillian Board, David Hemery, David Bedford, Steve Jones, Kirsty Wade and Linford Christie OBE.
In the town, the torch is used to light the Nos Galan Beacon, signalling the start of the senior races.
Mystery runners of the past few years
Shane Williams and Ian Evans
British Lion and Wales rugby legend Shane Williams was the 2011 Nos Galan Mystery Runner, accompanied by Wales and Ospreys team mate Ian Evans.
Shane, 34, was capped 87 times for Wales and retired from international rugby with a spectacular try in the last minute of the game against Australia in the Millennium Stadium, Cardiff, on December 3. He continues to be a key player with regional side Ospreys
Ian Evans, 27, lives in the Cynon Valley and began his rugby career with Abercwmboi RFC.
Capped 17 times for Wales, he also played in Shane’s last game at the Millennium Stadium in December 2011 and is hoping to be included in Warren Gatland’s Six Nations Squad 2012.
John Hartson and Mark Taylor
John Hartson is a former Welsh international footballer, best known for his time with West Ham and Celtic. Hartson featured prominently for Wales, earning 51 caps until his international retirement in 2006. He retired from professional football in January 2008.
Mark Taylor made his debut for Pontypool in 1992 before joining Swansea and was the Welsh Player of the Year in 2000. In the 2003-2004 season, Taylor was a member of the Llanelli Scarlets team that won the newly-formatted Celtic League.
James Hook and Jamie Roberts
Neath-born Hook represented Wales in the 2007 RBS Six Nations and was included in Warren Gatland's Grand Slam-winning RBS Six Nations side in 2008. The fly half played in the 2009 Six Nations and the Lions tour of South Africa.
Newport-born Roberts was part of the U21 Grand Slam-winning Six Nations team in 2005. He was included in Warren Gatland's RBS Six Nations squad in January 2008 and the RBS Six Nations squad in 2009.
Linford Christie OBE
In an international career spanning 17 years, Linford Christie competed more than 60 times for his country and won more major championship medals (23) than any other British male sprinter. He was the British team captain from 1990, a year that saw him claim his second European Championships 100m title, and his first Commonwealth Games Gold, until his retirement from international athletics in 1997.
Unbeaten by a British athlete for eight years (until 1996) over 100m, he is the only European to have run below ten seconds. His fastest time, 9.87 seconds, recorded when he won the 1993 World Championship in Stuttgart, is the European record.
Pontypridd-born Kevin currently plays for the Newport Gwent Dragons and is a talented fullback with a wealth of experience in international rugby.
He initially played for his home town club, Pontypridd, then joined Swansea in 1998.
Kevin joined the Celtic Warriors when regional sides were formed in 2003, then signed for Newport Gwent Dragons in 2004.
Rhys's first victory was in 1999 Welsh Schools Championships. Rhys would go on to achieve the European Champion at Under 17, 20 and 23 Levels.
In 2005, following a double gold in the European Under 23 Champs in Erfurt, Germany, Rhys made his Senior GB debut in the World Athletics Champs in Helsinki, Finland, making the Semi Finals, equalling his personal best twice.
In Gothenburg, Rhys managed to snatch the bronze medal by one 100th of a second, beating the Olympic Bronze medallist in the process.
Rhys then claimed his second medal in the Championships, picking up a silver in the 4x400m relay. His relay success meant that Rhys was Britain’s most successful athlete in Sweden.
Gethin Jenkins, Martyn Williams, Rhys Thomas
After almost a 30-year wait, 2005 was Wales’s year and the team won the RBS Grand Slam! Our mystery runners were Cardiff Blues’ Rhys Thomas, Gethin Jenkins and RBS Player of the Championship 2005 Martyn Williams.
After winning almost every Youth British title in all cycling disciplines and re-writing the record books winning four Junior titles in a year, Nicole has gone from strength to strength. In her first year as a Senior she became the Gold Medallist in the 2002 Commonwealth Games Road Race and at present is ranked 5th in the World in her discipline.
The third highest scorer in Welsh International rugby. He has 35 international caps and has won all available domestic rugby honours, Celtic League, Welsh National League and Welsh Cup. Left his hometown club the Llanelli Scarlets, to join French outfit Montferrand in the summer of 2004.
Silver medal in 2002 400metre hurdles at the Commonwealth Games in Manchester. Silver in the 4x400m relay at the same event.
Gold Medal as part of the 4x100 relay team and bronze in the 200m at the commonwealth games in Manchester, Bronze 100m at the European Championships.
World Junior 100m and 200m Champion. European Indoor 200m Champion. Commonwealth Games 200m Silver medallist.
Garin Jenkins & Dai Young
Garin Jenkins - most capped Welsh hooker and front row forward. Played in all three Rugby Union World Cups - 1991, 1995 and 1999.
Dai Young - current Welsh rugby captain. Holds 40 Welsh caps. Has played in two British Lion Tours, one Rugby League World Cup and two Rugby Union World Cups.
Jamie Baulch - Gold in the European Championships, silver in the World Cup and bronze in the Commonwealth Games 4 x 400m relay.
40th Anniversary Nos Galan
Jamie Baulch & Ron Jones
Ron Jones - Former British & Welsh Team Captain. Commonwealth & European Bronze Medalist. Member of the World Record breaking British 4 x 110 yards relay team.
British Record Holder over 400m
European & Commonwealth 400m Champion.
Former WBO World Bantam weight Champion.
Wales’ most prolific international points scorer, British Lions Full back & Barbarians outside half.
Former WBO World Feather weight Champion.
Photography by Creative Design, Rhondda Cynon Taf County Borough Council.
Additional photography, courtesy of Mountain Ash Studios.