The parish church celebrates a weekly mass every Sunday at 8:30pm
The Church of Saint Nicholas (Czech: Kostel svatého Mikuláše) is a Baroque church in the Lesser Town of Prague. It was built between 1704-1755 on the site where formerly a Gothic church from the 13th century stood, which was also dedicated to Saint Nicholas.
The original Gothic Parish church of Saint Nicholas stood on the site of the present church which dated from the 13th century. In the second half of the 17th century the Jesuits decided to build a new church designed by Giovanni Domenico Orsi. A partial impression of the original planned appearance of the church at the time the Jesuits chose the initial plans by Giovanni Domenico Orsi in 1673 and laid the foundation stone is provided by the Chapel of St. Barbara, which was built first so that mass could be celebrated. The church was built in two stages during the 18th century. From 1703 until 1711 the west façade, the choir, the Chapels of St. Barbara and St. Anne were built.
The new plans involved an intricate geometrical system of interconnected cylinders with a central dome above the transept. The massive nave with side chapels and an undulating vault based on a system of intersecting ellipsoids was apparently built by Christoph Dientzenhofer. The pillars between the wide spans of the arcade supporting the triforium were meant to maximize the dynamic effect of the church. The chancel and its characteristic copper cupola were built in 1737-1752, this time using plans by Christoph's son, Kilian Ignaz Dientzenhofer.
In 1752, after the death Dientzehofer in 1751, the construction of the church tower was completed. During the years the church continued to expand its interior beauty. Following the abolition of the Jesuit Order by Pope Clement XIV, St. Nicholas became the main parish church of the Lesser Town in 1775.
During the communist era the church tower was used as an observatory for State Security since from the tower it was possible to keep watch on the American and Yugoslav embassies respectively and the access route to the West German embassy.
It has been described as "the most impressive example of Prague Baroque" and "without doubt the greatest Baroque church in Prague and the Dientzenhofers' supreme achievement".
The church excels not only in the architecture, but also in the decoration, mainly with the frescos by Jan Lukas Kracker and a fresco inside the 70 m high dome by František Xaver Palko. The interior is further decorated with sculptures by František Ignác Platzer. The Baroque organ has over 4,000 pipes up to six meters in length and was played by Mozart in 1787. Mozart's spectacular masterpiece, Mass in C, was first performed in the Church of Saint Nicholas shortly after his visit.
The 79 m tall belfry is directly connected with the church’s massive dome. The belfry with great panoramic view, was unlike the church completed in Rococo forms in 1751-1756 by Anselmo Lurago.