The Main Guard originally the courthouse of the Ormond Palatinate, the building has served various functions over the centuries, such as market house, barracks, public house and now a museum. In 1715, the Palatinate jurisdiction was extinguished.

The ground floor, consisting of a loggia (or gallery) of open arches, was converted into shops and had additional floors added around 1810. The Main Guard, with its distinctive clock tower, has been recently restored to its original form. Almost ten years of painstaking restoration, which included incorporating stone from nearby Cistercian ruins, resulted in a Heritage Award for Best Practice in Conservation in the Tipperary.

The building is open to visitors from April to September and guided tours available.