In the oldest part of the town, we can find the Gothic Holy Trinity church and the post-Augustinian monastery. The monastery of hermit Augustinians was founded in 1290. The western part – which is the oldest – was erected most likely at the turn of the 13th and the 14th centuries. According to historical accounts, already in 1301, Bishop Henryk allowed the non-anathemized deceased to be buried inside the church. Several dozen years later, a four-bay west aisle was built along with a chapel adjacent to the aisle from the south. In March 1388, Jan, Bishop of Kamień, dedicated the church to the Holy Trinity. In the subsequent years, the extension of three-wing monastery building with an internal cloister, which neighboured on the church from its south side.
The Augustinian monastery was successful till the 16th century. In 1536, during the Reformation, after the friars abandoned the complex, a school and a hospital was set up in the monastery buildings; the church was used as a storehouse. Sources informing us about the post-Augustinian complex are focused mainly on the Holy Trinity church. It is known that a hospital was established in the southern wing of the monastery in 1558, where the patients moved from the Holy Spirit hospital and from the St Nicholas hospital were treated. Four years later, in 1562, the artisans’ guild prepared rooms for ill craftsmen. In the years 1619-1620, there was the Beguines’ house located in the eastern wing (in 1820, the eastern wing was pulled down due to its poor condition).
In 1697, the western wing changed its function once again – a municipal school was located there till 1791. In this period, the southern wing was used as teachers’ accommodation. When the school was moved to new buildings, the post-monastery rooms were purchased by a townsman. The convent hall was divided into three storeys, windows were bricked up, and the entire building was adapted for the residential purposes and for cloth manufacture. In the interwar period, there were private flats in the monastery.
During the Second World War, the monastery buildings did not suffered any particular damage. The buildings, which were slightly damaged in 1945, were rebuilt in the years 1959- 1965. One of the monastery’s wings was renovated in the years 1985-1988. Also, the surrounding of the complex was developed. Nowadays, the mediaeval complex is one of the most valuable historic monuments in Chojna. In the convent hall, a stellar vault has been preserved; up to this day we can admire monastery cloisters, numerous mascarons, and two columns preserved in a refectory.
Currently, the monastery wing has been adapted for residential purposes, including religious education classrooms.