Nice.
A link to Ray’s MTB Indoor Park in Cleveland, that marko mentioned: http://www.raysmtb.com/
Hungary has the "Underworld Cup", an underground mountain bike race:
Way of the arrangement: In 5 different runs - where professionals and amateurs may compete separately - maximum 70 racers may start. The ground is 2 km long and the runs will last for 60 - 80 minutes, depending on the category. A part (700 meters) of the course is be developed in a 150 year old tunnel system cut into stone at 10 meters under the ground level, where the starters may drive in unparalleled mood. The cellar is of varying internal height, of 2-2,5 meters in average and the width of the passages varies between 3 and 6 meters, however, one or two narrow and low sections will also increase the excitement.
https://www.youtube.com/watch?v=yX6Bm1xIWvk
2014-12-16 23:02:03