Porto Alegre
Porto Alegre is the capital and largest city of the Brazilian state of Rio Grande do Sul[^c1]. It is the southernmost state capital in Brazil and the centre of the country's fifth-largest metropolitan area, with approximately 4.1 million people in its urban region and 1,332,845 in the municipality itself at the 2022 census[^c2][^c9]. IBGE's 2026 estimate places the municipal population at 1,388,791[^c10]. The city sits on the eastern bank of the Guaíba, a large water body formed where the Jacuí, Sinos, Gravataí and Caí rivers converge before draining into the Lagoa dos Patos[^c3]. Its position on a navigable waterway made it a commercial and industrial centre from the colonial period onward.
Founded as an Azorean settlement in the mid-eighteenth century and elevated to a parish on 26 March 1772, Porto Alegre became the capital of Rio Grande do Sul in 1773. It grew through immigration, port trade and industrialisation, and by the twentieth century it had become one of Brazil's largest and wealthiest cities. Its historic centre preserves a dense ensemble of colonial, imperial and eclectic buildings, while the surrounding metropolitan region concentrates industry, services and a significant share of the state's economic output. The city presents itself as a diversified economy and a political protagonist, consolidated as a cultural and economic pole of national relevance[^c6].
Porto Alegre is best known internationally for two innovations in democratic participation. It became famous as the first city to implement participatory budgeting[^c4], a model later adopted across Brazil and the world. It also hosted the first editions of the World Social Forum, including the 2003 edition, which attracted 20,763 delegates from 130 countries and an audience of about 100,000 people[^c5]. These initiatives, together with its universities, cultural institutions and football clubs, shaped the city's reputation as a laboratory of civic innovation and a centre of gaúcho culture. Porto Alegre is one of the few cities with two world-champion football clubs, Internacional and Grêmio[^c8].
The city faces substantial social and environmental challenges. It is highly unequal, with well-structured central districts alongside precarious peripheral neighbourhoods, and it has experienced demographic decline and population ageing since 2010. Its low-lying areas are exposed to flooding, a vulnerability dramatically demonstrated in May 2024, when the historic centre alone recorded 6,558 affected residents and 8,115 affected businesses[^c7]. Recovery, urban regeneration and climate adaptation are now central themes of municipal policy. The POA Futura programme combines flood protection, sanitation, mobility, health, education, urban regeneration and social inclusion[^c11], with about R$4.2 billion allocated to resilience and protection[^c12], alongside the revitalisation of the historic centre, the future of public transport and the reduction of social inequality.