Museum of Northern Mazovia

The museum's collection consists of over 25 thousand exhibits presented in six departments: historical, ethnographical, archeological, art, numismatical, and amber. There are three permanent exhibitions dedicated to the history of the city, amber, and beautiful gas lightings. The most known and appreciated is "Amber from the basin of Narew". It consists of resinous fossils of various shapes and sizes, tools for treating them, and amber wares.

Museum of Northern Mazovia in Łomża was established in 1948 on the initiative of Adam Chętnik. In the past, collections were situated in three departments: war damages of Łomża Land, geological and paleontological, and the ethnography and folk culture, which was located in the outdoor museum in Nowogród. In the beginning, the facility operated in a rented apartment. Nowadays, it occupies the 19th-century tenement house where, until recently, a primary school was located.