Set in the middle of Main Town, St Mary's Church is believed to be the largest old brick church in the world. It is 105m long and 66m wide at the transept, and its massive squat tower is 78m high. About 25,000 people can be easily accommodated in its 5000-sq-metre (0.5-hectare) interior. It's a fascinating building to look at even from a few streets away, as its weathered red brickwork looms in a somewhat sinister manner over the much smaller, more thoroughly redecorated buildings at its feet.

The church was begun in 1343 and reached its present gigantic size in 1502. It served as the parish church for the Catholic congregation until the Reformation blew into Gdańsk, and it passed to the Protestants in 1572, to be used by them until WWII. The church didn't escape the destruction of 1945; half of the vault collapsed and the interior was largely burnt out. Fortunately, the most valuable works of art had been removed and hidden before the battle front arrived. They were brought back after a long and complex reconstruction. The church's elephantine size is arresting and you feel even more antlike when you enter the building. Illuminated with natural light passing through 37 large windows (the biggest is 127 sq metres in area) the three-naved, whitewashed interior, topped by an intricate Gothic vault, is astonishingly bright and spacious. It was originally covered with frescoes, the sparse remains of which are visible in the far right corner. Imagine the impact the church must have made on medieval worshippers. On first sight, the church looks almost empty, but walk around its 30-odd chapels to discover how many outstanding works of art have been accumulated. In the floor alone, there are about 300 tombstones. In the chapel at the back of the left (northern) aisle is a replica of Memling's The Last Judgment - the original is in the National Museum. Note the extraordinary Baroque organ. The high altar boasts a Gothic polyptych from the 1510s, with the Coronation of the Virgin depicted in its central panel. Large as it is, it's a miniature in this vast space. The same applies to the 4m crucifix high up on the rood beam. Directly below it is a lofty wooden sacrarium from 1482, elaborately carved in the shape of a tower.