Upvote:3
Just outside the airport there is Monumento ao Laçador. 9 min by car from the airport there is the football stadium Arena do Grêmio. 15 min you get to Park Farroupilha and 20 min you get to the historic downtown, Saint Peter Theater and the Metropolitan Cathedral.
Upvote:5
From the Salgado Filho International you can get on the "Trenssurb" ( a kind of underground ) to Mercado. Mercado is the name of the station of the Old Town of Porto Alegre. I believe this is the best option to do a small trip like that.
Some option to visit there:
I really like visit the Mercado where do you find few small stores with manufactured products and native fructifies, vegetables and of course meat. Porto Alegre is the capital of the State of the Churrasco ( it means BBQ ).
Also I really recommend to you visit Casa de Cultura Mario Quintana. Mario Quintana was a writer. Mario Quintana is considered the "Poet of simple things". He's house is a place with a lot of culture where do you find space to have a really good coffee.
These places Praça da Matriz, Praça da Alfândega, Paço Municipal and Rua da Praia are parks. Big parks with a lot of points to visit around there.