Bucharest&#39;s half marathon takes place on Sunday&nbsp;May 15th, on a 21km circuit which starts and finishes at Casa Poporului, taking in Piata Unirii and the National Stadium along the way. Besides the main half marathon, there are a number of shorter events, including a relay, and two children&#39;s races the day before. You can register online <a href="http://www.bucuresti21km.ro/en/registration/">here</a>, right up until May 14th.