Rzekuń is a rural municipality located in the Masovian Voivodeship, within Ostrołęka County, with its administrative seat in the village of the same name. The administrative history of Rzekuń dates back to the years 1921–1939, when it belonged to the Białystok Voivodeship, and from 1975 to 1998, it was part of the Ostrołęka Voivodeship. In 2004, the municipality had 8,902 inhabitants, and according to data from 2002, it covered an area of 135.5 km², of which 65% was agricultural land and 28% was forested. By 2018, the area of the municipality had decreased to 130.67 km². The municipality has a rich demographic history; according to the 1921 National Census, it was inhabited by 7,895 people, the majority of whom were Catholics. Rzekuń also includes several village districts (sołectwa), such as Borawe, Czarnowiec, Daniszewo, and Rzekuń, as well as non-administrative villages like Czarnowiec (a forest settlement). The municipality is surrounded by other gminas, such as Czerwin, Goworowo, and Ostrołęka. Thanks to its location and well-developed transport infrastructure, Rzekuń is a place where tradition meets modernity, making it an interesting point on the map of Masovia. The local culture and diverse architecture, shaped by the region's long history, are also noteworthy.