"St. Mary's Church (Polish: Bazylika Mariacka, German: St. Marienkirche), or formally the Basilica of the Assumption of the Blessed Virgin Mary (Polish: Bazylika Mariacka Wniebowzięcia Najświętszej Maryi Panny w Gdańsku), is a Roman Catholic church in Gdańsk, Poland. Its construction began in 1379. With its volume between 185,000 m³ and 190,000 m³ is currently one of the two or three second largest brick church in the world, and one of the two or three largest north of the Alps. Only San Petronio Basilica in Bologna, comprising 258,000 m³ is larger, Munich Frauenkirche and Ulm Minster also comprise 185,000 to 190,000 m³.
Between 1536 and 1572 St. Mary's Church was used for Roman Catholic and Lutheran services simultaneously. From the 16th century until 1945, when Danzig became Polish Gdańsk, it was the second largest Lutheran church in the world. It is 105.5 metres (346 ft) long, and the nave is 66 metres (217 ft) wide. Inside the church is room for 25,000 people. It is an aisled hall church with a transept. It is a co-cathedral in the Roman Catholic Archdiocese of Gdańsk, along with the Oliwa Cathedral." Wikipedia - St. Mary's Church, Gdańsk