Situated on the banks of the River Adaja, San Segundo church was built in Caleno granite between 1130 and 1160. Before it was dedicated to St Segundo after the remains of the town's first Bishop were found in 1519, it had been dedicated to St Sebastian and St Lucia. The Bishop's remains were moved in 1615 with great pomp and ceremony to the chapel of St Segundo, which was built on to the apse of the Cathedral specifically as a final resting place.
The layout draws inspiration from the basilica style and has three naves and an upper end with three apses closed off with calotte and barrel vaults. Its slightly off-centre north-eastern orientation is probably due to the existence of an earlier church or an error made when the construction was being marked out. The southern porch has five archivolts set on columns and there are others of similar characteristics to the North and West, which were replaced in the 16th century. The structure of the naves was replaced in 1521 with a structure that shows Mudejar-style influences. Its current appearance is the result of refurbishment work that was carried out as from the 16th century.
The decoration with Romanesque sculptures is limited to a number of capitals with plant and figurative motifs. Inside, it boasts a sculpture of St Segundo in prayer by Juan de Juni.
There is a Roman altar stone opposite the west entrance that was found during recent archaeological work on the church.References:
The Kalozha church of Saints Boris and Gleb is the oldest extant structure in Hrodna. It is the only surviving monument of ancient Black Ruthenian architecture, distinguished from other Orthodox churches by prolific use of polychrome faceted stones of blue, green or red tint which could be arranged to form crosses or other figures on the wall.
The church is a cross-domed building supported by six circular pillars. The outside is articulated with projecting pilasters, which have rounded corners, as does the building itself. The ante-nave contains the choir loft, accessed by a narrow gradatory in the western wall. Two other stairs were discovered in the walls of the side apses; their purpose is not clear. The floor is lined with ceramic tiles forming decorative patterns. The interior was lined with innumerable built-in pitchers, which usually serve in Eastern Orthodox churches as resonators but in this case were scored to produce decorative effects. For this reason, the central nave has never been painted.
The church was built before 1183 and survived intact, depicted in the 1840s by Michał Kulesza, until 1853, when the south wall collapsed, due to its perilous location on the high bank of the Neman. During restoration works, some fragments of 12th-century frescoes were discovered in the apses. Remains of four other churches in the same style, decorated with pitchers and coloured stones instead of frescoes, were discovered in Hrodna and Vaŭkavysk. They all date back to the turn of the 13th century, as do remains of the first stone palace in the Old Hrodna Castle.
In 2004, the church was included in the Tentative List of UNESCO"s World Heritage Sites.