St. John's Cathedral is Warsaw's main cathedral and one of the key historic churches in the Old Town. The building seen today is a post-war reconstruction, rebuilt after its destruction in World War II in a sober Masovian Gothic style.
It is worth stepping inside while walking between Castle Square and the Old Town Market Square. The cathedral's importance is as much historical as architectural, tied to royal ceremonies, national events, and the wartime destruction and rebuilding of Warsaw.