Called the Elfstedentocht (or in English, the Eleven Cities Tour), the race is a roughly 200 kilometer trek across the frozen landscape and takes, at its fastest, over six hours. For the race to occur, the ice must be at least 15 centimeters thick throughout the course — which is rare. While the tradition of skating from city to city dates back to 1760, the race was not formalized until 1909. In the century-plus since, the Elfstedentocht has only taken place 15 times and not since 1997. [...]
If the race occurs in 2012, area officials expect as many as 15,000 skaters — and more than ten million viewers watching on television. Nearly 2 million fans will travel to the region as spectators — an absolutely enormous number given that the total population of the Netherlands is only about 17 million, and doubly so given that the race only occurs at sub-zero temperatures.
Link | News Story | Photo: Flickr user nikontino
Last year it was extremely cold, see pictures here http://www.savonsanomat.fi/video-kuva/kuvasarjat/finland-ice-marathon-2011-kuopio/648050