The most famous Baroque church in Prague is also one of the most valuable Baroque buildings north of the Alps. The dome has an impressive diameter of 20 m, and the interior height to the top of the lantern is over 49 m, making it the highest interior in Prague. It is also an outstanding example of high Baroque decoration. Concerts are held in the church year-round on the historic organ dating to the 18th century. There used to be a Gothic parish church of St. Nicholas at Malostranské náměstí Square consecrated in 1283. This church was handed over to the Jesuits after 1620 within the framework of re-Catholicization due to Albrecht of Valdštejn, and the parish was transferred to the neighbouring St. Václav’s Church. The Jesuits established their first professional house in the parish building at Malá Strana in 1626. Over the following years, the Jesuits gradually extended their coverage at Malá Strana. Two more years later, they opened a primary school and a junior secondary school. With the support of the Kolowrat family, they planned to build a new church and to build a new professional house, and so they bought out the adjoining land plots - gardens, parishes, schools and 12 houses. The old St. Nicholas church was demolished and in 1673, the foundation stone was festively laid to the construction of the new Jesuit professional house and the new church. The neighbouring St. Václav’s church also stood in the way of the construction, and so it was also demolished and built a bit further away, in the corner of the professional house’s wing. However, the construction of the church according to the original plan of Domenico Orsi kept prolonging, and the construction therefore only began in 1703.