The South Wales derby is part of 90min's 50 Biggest Derbies in the World Series.
Isn't Wales a beautiful country? Stunning national parks, dazzling coast lines and a proud, distinctive culture.
And yet the nation that brought us Tom Jones, Dylan Thomas and 50% of Gavin and Stacey is also responsible for one of the fiercest, most bitter and hate-filled football rivalries in the world.
A full 40 miles separates South Wales rivals Cardiff and Swansea. Surely local rivals who are 40 miles apart can't hate each other that much?
Try explaining that theory to members of the South Wales police force.
The geographical distance between Cardiff and Swansea cannot dilute the intensity, bitterness and hatred between the two sets of supporters. The fans quite frankly detest each other, and don't keep their ill feelings to themselves.
The hooliganism that had English football by the scruff of the neck in the 1980s was a major component of Swansea versus Cardiff encounters.
In 1988, Cardiff won 2-0 at Swansea in the League Cup thanks to goals from Paul Wheeler and Terry Boyle. At full time, Swansea supporters chased 30 Cardiff fans onto the beach and into the sea. The police eventually managed to force the Swansea fans away, and the Cardiff faithful emerged from the waters dripping wet. Swansea fans still wear swimming caps and armbands on derby day.
During Swansea's 2-1 FA Cup victory over Cardiff in 1991, Swans goalkeeper Roger Freestone found £65 worth of coins in his goal mouth. They had been thrown at him in the space of one half.
In 1993, fan violence got so extreme that away supporters were banned from games. Hooliganism and fights were rife in UK football during the time, but the South Wales derby was the first fixture to enforce such stringent measures.
Away supporters were not allowed to attend the derby again until 1997.
The ban came in following the infamous 'Battle of Ninian Park'. Swansea fans tore up seats to hurl at Cardiff supporters, who then invaded the pitch to confront them.
Today, escorting away fans to the South Wales derby is carried out like a military operation.
Swansea and Cardiff fans are a versatile bunch, with fights between the two not just restricted to derby day. Other locations the two sets of South Wales fans have clashed include Italy, during a Wales Euro 2004 qualifier, and at Newbury Race Course during the horse racing festival.
The venomous hatred between the pair stems from socio-political issues in Wales. Cardiff is perceived as the favourite child; the glamorous capital city that receives all the investment, all the infrastructure and all the limelight. In comparison, Swansea is treated as the inferior, less successful sibling.
In 2001, Cardiff got the Senedd - the new Welsh Assembly building. Swansea got a new swimming pool.
The hatred rubs off on the players too. When Swansea won the Football League Trophy at the Millennium Stadium in Cardiff in 2006, Lee Trundle and Alan Tate celebrated by brandishing a Welsh flag emblazoned with 'F*** off Cardiff'. Not quite as classy as 'Wales. Golf. Madrid' but I suppose tastes come in and out of fashion.
What makes this display of animosity towards Cardiff from Tate and Trundle all the funnier is the fact that the pair had never even played in a South Wales derby at that point. Neither player had actually faced Cardiff City in a Swansea shirt. They just knew it was their duty as Swansea City players to detest Cardiff.
This is another interesting facet to the South Wales derby. Because the pair have such a history of yo-yoing between divisions, they can go years without meeting. Following Cardiff's promotion from the Third Division in 1999, the two sides did not play each other for nine years, leaving the hatred to simmer and fester.
They swiftly made up for lost time by meeting three times during the 2008/09 season after Swansea were promoted to the Championship.
Thanks to the clubs' shared habit of flitting between leagues, Swansea and Cardiff have met in each of the top four tiers of English football. Both sides have come close to rock bottom; Cardiff were plagued by all manner of financial troubles throughout the noughties, while Swansea were famously 90 minutes away from dropping out of the Football League in 2003.
A decade later, the pair met in the Premier League for the first time in their history. Not many rivalries in world football can claim to have materialised across such a spectrum of circumstances.
It's also an incredibly tightly contested rivalry. No team has ever done the double over the other.
This is the beauty of the South Wales derby; it is competitive, it has graced all flights of English football, and at its core, it is absolutely bonkers.
Source : 90min