The building currently belongs to the Museum of the Masovian Countryside. It was built in the years 1837-41 in the classical style. A characteristic feature of the building is the main facade decorated with a decorative groove system, called rustication, which gives the facade a sublime character.
The building has a square tower with a clock, from which every hour a bugle call specially composed for Sierpc sounds.
For almost 140 years, the town hall served as the seat of the city authorities, then it was handed over to the Museum of the Mazovian Countryside. The interior has been adapted to the presentation of exhibitions, a city library has also been created with historical books on the region and a lecture hall.
The Town Hall is a place of meetings with authors, lectures and lectures. Temporary exhibitions, Christmas product demonstrations and "St. Andrew's evenings" are also organized.