Oliwa Cathedral, formally known as the Archcathedral Basilica of the Holy Trinity, is a Roman Catholic church located in the district of Oliwa, within the city of Gdańsk, Poland. Completed in the late 14th century in a Brick Gothic style, the present church comprises Mannerist-Baroque architectural elements. It has been one of Poland's protected Historic…Oliwa Cathedral, formally known as the Archcathedral Basilica of the Holy Trinity, is a Roman Catholic church located in the district of Oliwa, within the city of Gdańsk, Poland. Completed in the late 14th century in a Brick Gothic style, the present church comprises Mannerist-Baroque architectural elements. It has been one of Poland's protected Historical Monuments since 2017, particularly due to its historical significance and the great organ inside.