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".
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.