Castle of the Teutonic Knights - Taking advantage of the marshy terrain of the Nida valley the Teutonic Knights built a wooden guard castle on the hill. The first mention of it was made in 1376. The fortification extension resulting in one of the biggest single-wing residential and fortified castle was completed about 1400.
It became a seat of the Order commander and it was to protect numerous villages established by the Order in the region of Dąbrówno, Olsztynek and Działdowo against retaliatory campaigns of the Lithuanians. At the beginning of the 16th century the castle was converted and the approaches of the castle were equipped in 1517 with surrounding walls and a bastile on a circular plan adapted to firearms. In its history the fortification was besieged several times. In the 19th century the castle was seriously destroyed by the troops stationing here. The fortress was saved from the total devastation by a court counsellor of Nidzica, Ferdynand Tymoteusz Gregorovius. Thanks to him the castle was reconstructed in 1830 and used as a seat of offices, private apartments as well as a prison. In 1945 a part of the castle rooms were burnt down. In 1965 the magnificence of the castle was restored together with its former decor.