Frombork's massive 14th-century Gothic Cathedral (1329 - 1388) is the main focal point of the town. A masterpiece of brickwork, the breathtaking interior is packed with Baroque altars and tombstones, and features a gigantic 17th-century Baroque organ, one of the most famous organs in the country. Recitals are often given, though must be booked for 13zł and with a minimum of 20 people, and the Cathedral plays host to an annual organ festival during the summer. In a cathedral full of wonderful sights, the most keenly sought is the grave of Nicolaus Copernicus, which you'll find half-way along the right hand most aisle as you walk into the cathedral. Other sights of note are the late Gothic altar in the northern nave which was donated in 1504 by Copernicus’ uncle, Bishop Watzenrode; a crucifix in the rainbow arch dating to the end of the 15th century; a painted epitaph to the canon Bartłomiej Boreszow which is dated to around 1420; an 18th century epitaph to Copernicus found on the first northern pillar of the main nave as well as remains of Gothic stalls and Gothic and Renaissance tombstones. It’s worth remembering that as well as Frombork being the place where Copernicus carried out most of his research, this cathedral was also where he spent more than 30 years as a canon and would have spent much of his time in pastoral work.