The museum's collection includes a medieval, richly carved cross from the Clogher Abbey and items from prehistoric stilt villages built on the surrounding lakes.
The museum was established in 1974. It is housed in a 19th-century building in the center of Monaghan. Its collection includes items from various periods in the history of the region, from prehistory to modern times. The most significant collections concern the most ancient history. The elements of equipment for stilt huts, the so-called crannog, which were built by the local population, are gathered here. There are jewelry, weapons, utensils and even leather shoes. Equally valuable are items from the Clogher Abbey, including a cross made of oak wood, decorated with scenes from the life of Christ and Celtic motifs.
The rest of the exhibition is about the everyday life of the people of Monaghan. There are furniture, home furnishings, documents, letters and photos. Much space was devoted to the traditions of the fight for independence and to participants of subsequent insurrections.