Saint John's Eve and the first day of the Midsummer celebrations (although this is not the real summer solstice; see June 20) (Roman Catholic Church, Europe): First night of Festa de São João do Porto (Porto)

Festa de São João do Porto is a festival during Midsummer, on the night of 23 June, in the city of Porto, in the north of Portugal, as thousands of people come to the city centre and more traditional neighborhoods to pay a tribute to Saint John the Baptist, in a party that mixes sacred and profane traditions.

Porto, also known in English as Oporto, is the second largest city in Portugal, after Lisbon. It is the capital of the Porto District and one of the Iberian Peninsula's major urban areas. Porto city proper, which is the entire municipality of Porto, is small compared to its metropolitan area, with an estimated population of just 252,687 people in a municipality with only 41.42 km² (16 sq mi). Porto's urban area has around 1.4 million people,(2025) in an area of 2,395 km² (925 sq mi), making it the second-largest urban area in Portugal. while the Porto metro area surpasses 1.8 million people. It is recognized as a global city with a Gamma + rating from the Globalization and World Cities Research Network.