The St. Olaf's Church in Tyrvää is a late medieval stone church built probably in 1510-1516.
Archeologists have found evidences that the church site has been a spiritual place even in 1000 BC. The settlement has concentrated to the Vanhankirkonnimemi area during the end of Iron Age. There may have been two wooden churches before the present one built in the 14th century. The St. Olaf's Church was probably extended in the 17th century by local family of Nuutila.
When the new wooden church was completed in 1855, St. Olaf's church was abandoded for one hundred years. The church was well known of it's unique interior, until it was burnt down by a pyromaniac in 1997. The church was rebuilt by local people and the interior paintings were created by painters Kuutti Lavonen and Osmo Rauhala.
Finnish National Board of Antiquities has named the church site as national built heritage.
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.