Rua Goncalo de Carvalho is a street located in Porto Alegre, the capital and largest city in the Brazilian state of Rio Grande do Sul. Flanked by trees on either side, the street became internationally known after a campaign for its preservation spread on the Internet leading it to be dubbed "the most beautiful street in the world".
Over a span of 500 meters the sidewalks are lined with more than one hundred Rosewood trees, going up to the seventh floor of the buildings in some cases. According to some elderly residents, the trees were planted in the 1930s by employees of German origin who worked in a brewery in the neighborhood.
In 2005, the construction of a mall nearby brought the risk of changes to this beautiful street, prompting residents to mobilize. The campaign was successful, and on June 5, 2006 the then mayor José Fogaça signed a decree making the street Gonçalo de Carvalho "historical, cultural and environmental development of the city."
Photographs of the street circulated among environmental groups, and the "tunnel of trees" become increasingly popular. In 2008, a Portuguese biologist saw the pictures and wrote in his blog that it was the most beautiful street in the world. The nickname caught and the street has thus been called by several publications ever since.
Source: Wikipedia