Entry number 6 in my unusual and extreme sports series is Horseball.
From what I've seen so far I can say that this sport is intense. It's been called a mix of polo, rugby and basketball but that cannot really do it justice. Players gallop around on horseback flinging a ball to each other while trying to throw it into giant hoops placed either end of the arena.
The ball is essentially a football wrapped in a harness and the first difficulty seems to be picking it off the ground while remaining on the horse. Once you've managed that you can only hold onto the ball for 10 seconds and the ball has to be passed a certain amount of times between teammates before an attempt at goal can be made. All the while the opposition are within rights to barge into you and rip it off you. It's basically a contact sport on horseback and spectacular to watch.