The running of the bulls (Spain): Every July, more than 1,000 runners participate in Pamplona's annual bull run -- when revelers try to outrun the charging bulls through the streets in the city's old quarter.
PEDRO ARMESTRE/AFP/Getty Images
The Iditarod sled dog race (USA): The great race across Alaska lasts for at least eight days, covers more than 1,000 miles and takes place in temperatures as low as -50C (-58F).
JIM WATSON/AFP/AFP/Getty Images
Chernobyl (Ukraine): TheChernobyl nuclear power plant, as well as