The Church of St. Nicholas the Wonderworker is a Russian Orthodox church built between 1825 and 1827 on an old Russian church according to the plans drawn up in 1807 by the architect Luigi Rusca. The neoclassical church is one of the first domed churches in the capital.
The Cathedral of the Transfiguration in Tallinn is an Estonian Orthodox Apostolic Church. The church building was built in the 13th century as the church of the Convent of St. Michael in Tallinn. In 1629 the monastery was secularised. In February 1716 the Russian garrison regiment used the church until its reconstruction. After the reconstruction, the main church was consecrated in 1734 and was the Orthodox Cathedral until 1900, when Alexander Nevsky Cathedral was completed. A tower was built for the church in 1776, the present windows, the main door and the roof dome were completed in 1827-1830.
St. Peter and Paul's Cathedral was designed by Carlo Rossi and completed in 1841. It is the Catholic Cathedral of Tallinn. During the period of Swedish rule (1561-1721) Catholicism was banned. When Sweden ceded Estonia to the Russian Empire at the end of the Great Northern War, the new authorities introduced religious freedom. In 1799, the Catholic parish grew and took over the use of the former refectory of St. Catherine's Monastery, which had remained closed since the ban. The refectory was used as a place of worship and is located on the site of the present church. In 1841, as the place of worship had become too small, a new church was designed by Carlo Rossi.