Up and running since 2005, the Caminhada Noturna ('Night Walk') strays from the usual walking-tour territory in that the itinerary isn't fixed, and in its noble aim of trying to raise awareness of the need to revitalise the city centre.
Two hours long, the tour often draws a following of up to 100 people. It's run by the owner of vegetarian restaurant Apfel though walks are often led by various experts on the city's history, culture and architecture.
All in Portuguese, the tour may change its route depending on what participants are most interested in, but usually includes the most important sites of the city, such as the Praça Roosevelt and the Edificio Itália – the city's second highest building, with a viewing platform on the 41st floor (though note, the viewing platform is not open to the general public at night).
The tour starts and ends at the Theatro Municipal.