It is the only remaining part of the former protestant church of mercy built in 1710. The present tower itself was built in 1846 from the initiative of Biron family and princess Dorothy Perigord – Talleyrand due to the project of an architect – Carl Heinrich E. Knoblauch. The brick tower has five floors. The top is made of iron and was made in a foundry in Iłowa. In the ground floor the is a ducal mausoleum and the entrance to the crypts. On the walls there are grave stones of the ducal family Biron. In the tops of the grave stones there are coats of arms of the family Biron. The tower was opened for tourists on October 29th, 2004. It serves as a view tower. One may see the surroundings of Żagań and during a sunny weather the Karkonosze Mountains are also visible. Inside the tower there is a small gallery.