Holy Trinity Church, Olyka
The Baroque collegiate church of the Radziwills of 1635–1640, modelled on the Roman Il Gesù, the family burial vault of the princes.
The first wooden church here was built in 1588 with the support of Prince Stanislaw Radziwill. The stone church was erected in 1635–1640 at the expense of Albrycht Stanislaw Radziwill to a design by Benedetto Molli and Giovanni Maliverna, modelled on the Roman church of Il Gesù. The basilica, 45 by 25 m, was consecrated on 26 August 1640 by the Bishop of Lutsk Andrzej Gembicki; in 1638 a college was founded at it. The church functioned until 1945; in the 1960s the tower and part of the wall were dismantled, and in the early 1990s the church was returned to the Roman Catholic parish. Since 2013 restoration has been under way at Poland's expense; in 2025 its tenth stage began.
The town of Olyka, 2 Tarasa Shevchenka Street (by the castle), 35–40 km from Lutsk (vsn.ua, 11.06.2026). The interior has been under restoration since 2013, services on feast days — arrange access inside with the parish.