The county was created in 1836, by dismemberment of the county of Maia and after to have been transferred to Town Hall, that was in Alfena in that today is the old zone of the city of Alfena. Very important place for the Romans, who have established mines of gold extraction here. Here came many working slaves, who after being freed mingled with the local people. Vallis Longus was called this area. Today it is the natural park of Valongo

Other important locals are the cities of Ermesinde and Alfena.

For centuries, a very important party has been held in Sobrado on S.João’s day, the festival of Bugios or Bugiadas, where fantastic masks representing Moors and Christians are exhibited in singular dances. Currently a candidate for Cultural Heritage of Humanity.

Annually are also organized plenty of cultural events as they as, The Magic Valongo, whose is one of the biggest international reference in illusionism. Valongo is internationally well-known by being the capital of roller hockey. Has also a club (Valong Sports Association) which is currently in the first league in every echelon (Under13, Under15, Under 17, Under20, Seniors and Veterans). The Under15 class from the Sports Association Of Valongo are the current national and districtal champions. The Seniors in the 2013/2014 season won the FC Porto by 5-3 and were thus consecrated national champions. The club is involved in big European and even world competitions. The team from Valongo was the first official roller hockey team in the world. Unlike other cities, the roller hockey is the top sport, all children starts playing it from childhood.

Valongo also welcomes a known trail running event, which takes place every year: “Trilhos do Paleozoico” (“Paleozoic Rail”).