St. Catherine's Church, Gdańsk
St. Catherine’s Church is one for the real history buffs as this is the oldest church in Gdańsk, dating back to the 14th Century. Originally, St. Catherine’s was a Protestant church in a city which has endured Teutonic times, the Prussian empire, Hanseatic times, the Free City of Danzig and the era of communist rule. Since 1945 however, it has been used solely as a Roman Catholic church. Of real significance, it has the world’s first ever pulsar clock, which uses radio pulses from pulsars to keep the time.