The Temple of St. Nicolas is considered to be the most beautiful Baroque building in Prague and it is also extremely valued on a European scale. As mentioned before, from the 1620 the original church was owned by Jesuits, who decided to build a new church and college. The foundation stone was laid in 1673 in the presence of the ruler, Leopold I, the Holy Roman Emperor and Czech King, which demonstrated the significance of this church. The construction of the massive church went slow the foundations were 15 meters deep. At the beginning of the 18th century, Christoph Dientzenhofer took over the construction and therefore, the Dientzenhofer family of builders is considered to be the main architects and constructors of the temple. Christoph Dientzenhofer started the construction by building two naves with aisles. He also most-likely built the most structurally challenging façade of the temple, which is a unique example of the so-called, Dynamic Baroque - that makes the illusion of the moving matter. The façade is decorated with statues by Bedřich Kohl and in the gable stands the statue of St. Nicolas and in the attic there are statues of Peter and Paul and the Jesuit saints, Ignatius and Francis Xavier. After the death of Christoph Dientzenhofer in 1737 his son Kilian Ignaz took over. He finished the third nave of the temple, built the dome and began to build a lean tower but he did not finish the whole building. After his death, his student and also his son-in-law, Anselmo Lugaro, finished the church. The size of the church is truly impressive and it is situated on the ground plan of 40 x 60 m. The height of the dome that includes a small tower, as well as the height of the bell tower is 79 m. The inside diameter of the dome is 17 m and the inside height is 50 m, which is the highest interior in Prague.
When the citizens of the Lesser Town first saw it, they feared that the slender and high tower would fall on their houses but they soon got used to it. The tower served as an observation tower, to guard and to report fires or any enemy movement. In the time of totality it served the same observation purpose and the members of the State Security monitored the movement of people and events in the local Western embassies from the tower.
The interior of the temple is a fine example of the Baroque church architecture and the expression of Baroque lifestyle philosophy. The decoration of the temple, monumental, Baroque tension, sophisticated play of light and shadow and showy wealth, it made all the believers, who were coming from the misery and suffering of the terrestrial world, feel more strongly the hope and salvation that God gives. The ceiling frescoes are the work of Johann Kracker and they represent the Celebration of St. Nicholas and scenes from his life. The fresco is 1500 square meters it is the largest fresco in Prague. Another significant fresco is the Celebration of St. Cecilia by Francis Xavier Palk, who also decorated the chapels with his famous painting, The Martyrdom of St. Francis Xavier. The statues are made by Ignaz Platzer and in the gallery, visitors can admire the Passion Cycle painted by Karel Škréta.
The temple is also linked with music because it is a place where church music concerts are frequently held. Amadeus Mozart played the rare church organ while he was staying in Prague. After his death, his Prague host, Josefina Dušková, organized the mourning in the church and the Requiem by Rossetti was performed during that memorial service. Today, if you attend one of the concerts you will have a memorable experience.