The Church of St Joseph is part of the Ursuline convent on Orlí Street. It was built in the mid-17th century, despite the reservations of the city council regarding this plan, as there were already fourteen beautiful churches in the town and its surroundings and little space for burghers’ houses.

After the convent building was expropriated in 1945, it was completely remodelled to serve the purposes of the Technical Museum, but after 1989 the convent was returned to the Order of St Ursula.

The crypt of the Church of St Joseph was made accessible from the convent courtyard by its second entrance (the first entrance is under the church floor) in 1994. It was discovered during the removal of an outdoor exposition when a crane pushed into a concealed corridor and broke its ceiling.

After opening the crypt, it was clear that the religious remains of the nuns, placed around the perimeter of the walls in the shafts 2.5 metres deep, had been disturbed, probably during a robbery. This was evidenced by the finding of a small tin coffin with a headless torso of a woman about 120-130 cm tall. This tiny person of aristocratic origin had been placed in the convent by her parents. The skeleton was dressed in a lavish pink dress with lace in a surprisingly well-preserved condition. A richly decorated coat of arms was painted on the coffin lid. After the exhumation in 1995, the remains of a total of one hundred and sixty nuns were reverently buried at the central cemetery. Other remains placed under the brick paving crypts were left in place.

The square space of the crypt, roofed by a strong compressed barrel vault, is well ventilated and in excellent technical condition. At the head of the crypt, between the two entrances, there is a stone plaque on the wall with the text: IN 1658 IN JUNE TAKEN TO GOD WAS ORDER SISTER POLYXENA BOCKISCH ENTERED THE ORDER AT THE AGE OF 32 BURIED HERE 8 YEARS LATER FOR THE GREAT DELIVERANCE OF HER SOUL MAY GOD BE MERCIFUL AMEN.