St. Nicholas Cathedral – the temple complex of the Russian Orthodox Church, located in the centre of Kazan on the street Bauman. It is a city landmark and a monument of religious architecture. Since 1946, the Cathedral functioned as a Cathedral. The Cathedral is an architectural complex of administrative buildings, communicating intercession and Nikolo-Nyssa churches, bell towers and chapels.

Nikolo-Nyssa Church was named so in order to distinguish it from other Kazan churches, dedicated to Saint Nicholas. For example, from the Church of St. Nicholas Seating, which was located nearby.

Nikolo-Nyssa Church (Church of St. Nicholas) is a plastered brick building. The Church's exterior is decorated in an eclectic style, typical of the late 19th century. Near the Church classic construction: no columns, one head, one-apse. The main entrance is located on the West facade, located on Bauman street. The entrance is decorated with two sides of the rectangular niches. A second input is made from the side of the Church yard. The building has two tiers, decorated with flat, profiled blades. The second floor has rectangular Windows with architraves with a complex geometry with elements polycolonal and surmounted by pediments. The frieze is decorated with stucco decoration geometric shapes. The elements alternate with triglyphs above the blades. The building is finished with scalloped attic and dome on a drum having a curly form.

The Church is a monument of architecture, in the style of Russian Baroque. It was built in the late 17th – early 18th centuries Triapsidal Church of brick was once plastered. The temple pakistany, dome, with five bulbous domes, settled in the Byzantine style. At the temple almost cubic volume, multiple flat blades hanging. The volume concludes with bins of semi-circular form, decorated with flagstone. The double-height Church. The window openings have a semicircular shape and framed in luxurious trims in the Baroque style, with ogee-shaped canopies. Large and small light drums decorated belts with openwork ornament.

The bell tower in height that dominates over all the buildings of the complex. It was built in the early 18th century in the style of Russian Baroque. The five-tiered bell tower, with richly decorated walls of the tiers completed the drum is octagonal in shape, with an onion dome. Glaucus has a coating of flake ceramic tiles green color. The octagon belfry is reduced by the volume up and decorated with carved ornament and brick semi-columns.