The exhibition Treasure from Skrwilno and Nieszawa is housed in the medieval tower of the Town Hall. The treasure was deliberately hidden, possibly due to events associated with the Swedish invasion of Poland during the reign of Jan Kazimierz, and was found in 1961 during archaeological work carried out by the Toruń Museum in the grounds of an early medieval stronghold in Skrwilno, Dobrzyń (near Rypin). The Skrwilno treasure is widely regarded as one of the most important archaeological finds in Poland in the 20th century.