Church of the Holy Trinity (Uniates) and Basilian Monastery is a square basilica shape, with elements of Gothic, Baroque and Russian Byzantine styles. The first church on the site was built to mark the spot where three Lithuanian Christians martyrs Anthony, John and Eustace were martyred. Legend has it that in 1937 Grand Duke Algirdas’ wife Julijona built a wooden Orthodox Church in their honour.
In the 16th century the Church was funded by Constantin Ostrogishki as the Orthodox Church. Between 1608 and 1827 the Church belonged to the Uniates of the Basilian Order. Later the Church was given to the Orthodox Church and after independence it was returned to the Uniates.
Under the roof of the neighbouring buildings of the monastery an Orthodox printing-house was located, which in 1596 issued the first publication of the primer of the Eastern Slavs by L. Zizanius.