The complex consists of a parish church, the old monastery and school as well as a monastic granary, and is located in the north-west part of the old town.
The church dates from the beginning of the C13th. In the second half of the C14th nuns erected a three-nave basilica. After fires in 1472 the church was rebuilt. In 1515 the main nave was heightened and a new tower was erected on the west. After a fire in 1730 the rebuilt interior had a Baroque stucco-sculpted decor. The Augustinian Monastery currently serves as a presbytery and parish buildings.
The Augustinians, brought here in 1284 from Nowogród Bobrzański, acquired a parish church and a presbytery. In the mid-C14th they rebuilt the church, also erecting an abbatial palace. After the fire of 1730 it was redesigned in the spirit of the Baroque. Only a section of the rooms in the east wing have retained a Gothic character. Besides the original brothers’ I cells and a chapter-house there is a Chapel of St. Anne with Gothic vaulting and a monastic library with C18th decor. The interior of the library is decorated with frescoes executed by the artist G. W. Neunherz. The medieval book collection of the library was taken away to Wrocław in 1810. It survived the last war and is currently the richest preserved medieval monastic library collection in Poland. The library interior is known for its perfect acoustics thanks to one of the few so-called “whispering galleries” in the world. The Monastic Granary (malt house) is Late-Gothic from the end of the C15th, partially transformed in the C19-20th. It is built from bricks with a front elevation divided up by narrow, lancet arcades.
In 1972-1975 it was rebuilt and adapted to become a tourist hotel. In the tower built for carrying out astronomical observations frescoes have’ been preserved linked to astronomy and the stay of Johannes Kepler in Żagań. In 1783-1795 the tower acted as a base for the world’s first meteorological network Societas Meteorologica Palatina.