Prague Half Marathon

You'd expect an international city like Prague to have an international marathon, and they got it, well, half-right. The Prague Half Marathon (or about 21 km, half of a traditional marathon's 42 km) is the world's most international marathon, with a majority of the runners coming from 55 different countries. The marathon might also be the fastest way to see the city, if ordinary walking tours bore you. The run begins at the Charles Bridge and the runners wind their way through the Jewish Quarter, Old Town and up to the National Theatre, then along the Vltava River to Vyton, crosses Palackeho Bridge to Na Kampe, and finishes on Na Kampe square for the grand finale (for those who make it). The registration fee is 35 Euro, and unfortunately for the speed walkers, there's a time limit of three hours.