The gatehouse is composed of a baroque style front entrance and a gate tower. The front entrance was designed by Augustyn Locci Mł. in 1674-75. The attic from 1730s was commissioned by Katarzyna of Sobieski Radziwiłł with a decoration to glorify the military actions of her husband Michał Kazimierz, co-victor of the battle of Chocim. On left side of the compositional monument there is "justice", on right "bravery". The tower from the first part of 17th century, was renovated around 1670, is currently the museum.