Belgium hosts a number of prominent annual competitions across all sections of the sport of athletics. The Memorial Van Damme, Belgium's foremost track and field competition, began in 1977 and is now part of the IAAF Diamond League circuit. Two of the meetings in the Lotto Cross Cup (an annual cross country running series) are sanctioned by the IAAF and European Athletics. Other significant competitions which are part of the European athletics circuit include the Flanders Indoor meeting in Ghent and the KBC Night of Athletics in Heusden. The country has two AIMS-certified marathons: the Antwerp Marathon and the Brussels Marathon. There is also an annual ultramarathon competition called the Nacht van Vlaanderen, a 100 km race which has been held annually since 1980. The meeting has also doubled as the European and IAU World Championships on a number of occasions. Other annual races of note are the Warandeloop, Oostende-Brugge Ten Miles, Kust Marathon, Guldensporenmarathon and the 20 km of Brussels.