The Institute of History of Art at Jagiellonian University in Cracow has joined the CARE project in 2015/2016 via cooperation with Jana Mařiková-Kubková at Archaeological Institute in Prague. Actual collection of the buildings includes 17 examples, which have been identified so far and 4 another archaeological sites with some architectural evidence awaiting a full revision. The current work on the CARE project in Poland involves collecting and analyses of the documentary evidence of archaeological sites. The working team has been organising due to current cooperation with the colleauges from the Institute of Archaeology and Ethnology of Polish Academy of Science (mainly Poznań and Warsaw) and the archaeological stations on Wawel Royal Castle in Cracow, Ostrów Lednicki etc. The Christian architecture on this land have appeared within the political activity of Piast’s house and forming the early state during the second half of the 10th century. The article presents the most interesting buildings in the context of their function and the broader relationships, also Christianisation and church organisation after baptism of duke Mieszko in 966.