In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

Where did the protesters' march conclude?, Context: Argentine activists told a news conference that they would not try to snuff out the torch's flame as demonstrators had in Paris and London. "I want to announce that we will not put out the Olympic torch," said pro-Tibet activist Jorge Carcavallo. "We'll be carrying out surprise actions throughout the city of Buenos Aires, but all of these will be peaceful." Among other activities, protesters organized an alternative march that went from the Obelisk to the city hall, featuring their own "Human Rights Torch." A giant banner reading "Free Tibet" was also displayed on the torch route. According to a representative from the NGO 'Human Rights Torch Relay', their objective was to "show the contradiction between the Olympic Games and the presence of widespread human rights violations in China"
the city hall