F.e. the marble columns from the demolished St. Alexander Church in Warsaw are now in the RC Wawel Cathedral in Kraków. AFAIK it's not the only one case.
I also recall the rubble from the demolished Resurrection Church in Białystok used in fence of the RC St. Roch Church in Białystok.
Read what Schultz wrote!
Anyways, the Gorazd mentioned in many of Isa's posts did not come to Kraków but to Wiślica, which was the capital of the region.
Here is the minor basilica of Wiślica.
Also, a temporary Byzantine exarchate existed in the city of Sandomierz for a couple decades in the 10th century.
Here are the churches of modern Sandomierz.
The Dominican convent of Sandomierz, founded by one of the Apostles of St.Dominic, St.Jacek(yA-tsek) who is called st.Hyacinth in English,French and other languages.
Church of the conversion of St.Paul, Sandomierz
Below is the cathedral of Sandomierz
If someone wants to gaze at Baroque and Roccoco please view these four galeries : http://www.katedra.sandomierz.org/galeria/index1.html
The Catholic Church of St.Nicholas, Kyiv, Ukraine
The church of st.John the Baptist in Bila Tserkva, Ukraine
The church of st. John from Dukla built in 1828-41
The cathedral of Zhytomyr, Ukraine st.Sophia built in 1737