Field hockey:
Game played on field similar size to soccer pitch. Eleven players on each team, only ONE (yes only one) of which is padded (the goalkeeper). Played with round ball, approximately size and weight of cricket ball. Players allowed to hit, push and "dribble" ball with only one side of stick (yes only one). Played out doors in winter.
Current Olympic Champs - Australia's Mens Hockey Team (the Kookaburras), Australian Women's Hockey Team (the Hockeyroos) won gold three times out of the last four (I think, may be out of last five).