The Roman Catholic Church of the Holy Cross was built in the Baroque style from 1751 to 1758. It is the oldest Catholic church in the city. Its construction began when the village of Csíkszereda, with a few hundred inhabitants, was granted parish status. In 1771, the Chapel of St. John of Nepomuk was added. With the development of the city, the church had already become too small by the beginning of the 20th century. However, the dream of the Catholic faithful for a new, larger church was not fulfilled until 2003: the magnificent Millennium Church was built right next to the Church of the Holy Cross.