The Obelisco de Buenos Aires (Obelisk of Buenos Aires) is a national historic monument and icon of Buenos Aires. Located in the Plaza de la República in the intersection of avenues Corrientes and 9 de Julio, it was erected in 1936 to commemorate the quadricentennial of the first foundation of the city. History Construction began on March 20, 1936, and it was finished on May 23 of the same year. It was designed by architect Alberto Prebisch (one of the main architects of the Argentine modernism who also designed the Teatro Gran Rex, in Corrientes and Suipacha) at the request of the mayor Mariano de Vedia y Mitre (appointed by president Agustín Pedro Justo). For its construction, which cost 200,000 pesos moneda nacional, of concrete and of Olaen white stone from Córdoba were used. The obelisk was built by the German company G.E.O.P.E. - Siemens Bauunion - Grün & Bilfinger, which completed its work in a record time of 31 days, with 157 workers. The rapid hardening Incor cement was used and was built in sections of to facilitate the dumping of concrete. Its height is , and of these are up to the initiation of the apex, which is . The tip is blunt, measuring and ends in a lightning rod that cannot be seen because of the height; its cables run through the interior of the obelisk. It has only one entrance (on its west side) and on its top there are four windows, that can only be reached by a straight staircase of 206 steps with 7 breaks every . On February 20, 1938, Roberto María Ortiz succeeded Justo as President and appointed Arturo Goyeneche as the new mayor of the city. In June 1939 the City Council sanctioned the demolition of the Obelisco, citing economic, aesthetic and public safety reasons. However, the ordinance was vetoed by the municipal executive power, characterizing it as an act without merit and juridical content, because it alters the state of things emanated by the executive power, and that it was a monument under the jurisdiction and custody of the Nation and is part of its heritage. Where the Obelisk stands, there was a church dedicated to St. Nicholas of Bari; it was demolished. In that church the Argentine flag was officially hoisted for the first time in Buenos Aires, in 1812. That fact is noted in one of the inscriptions