on the north side of the monument. As a result of the detachments of sheets of stone covering, which occurred on the night of June 20–21, 1938, the day after a public event with the presence of president Ortiz took place there. It was decided to remove such cladding in 1943 and was replaced by another one made of polished cement, making cracks to simulate the joints of the stones. When the slabs were removed, a legend that said "Its architect was Alberto Prebisch" was also removed. In 1973, it was decorated as a Christmas tree. In 1975, during the Peronist government of Isabel Perón, a ring-shaped rotating sign was hung around the obelisk, with the motto El silencio es salud (Silence is health). Although it was allegedly geared against motorists creating excessive noise, it was widely interpreted as a statement calling Argentines to refrain from expressing their political views. Throughout its history, the monument has suffered vandalism, especially politically oriented graffiti. In the 1980s, an activist group broke in and spilled paint from the top windows, causing the city government to erect a fence around its base in 1987. This move stirred controversy, but eventually proved effective in reducing the number of defacing incidents. On 1 November 2005 it was announced that a comprehensive restoration, financed by the Argentine painting and restoration industry association (Ceprara), was finished. The monument was painted with 90-micrometre acrylic paint to a "Paris stone" hue, deemed more pleasant than the previously used white. On December 1, 2005, the obelisk was covered by a giant pink condom to commemorate the World AIDS Day. To commemorate the 30th anniversary of the La Noche de los Lápices, the monument was converted into a giant pencil. Lines B, C, and D of the Buenos Aires Metro have stations near the monument, and are connected by a number of underground passages with commercial galleries. The Obelisco hosted the opening ceremony of the 2018 Summer Youth Olympics. Inscriptions on its sides At the base of the south face, in a very small rectangle, this sonnet written by Baldomero Fernández Moreno during a tribute dinner in the Alvear Palace Hotel to Prebisch: El Obelisco ¿Donde tenía la ciudad guardada esta espada de plata refulgente desenvainada repentinamente y a los cielos azules asestada? Ahora puede lanzarse la mirada harta de andar rastrera y penitente piedra arriba hacia el Sol omnipotente y descender