    [Sentence 1: When was St. John's Cathedral constructed?    [Sentence 2: The most significant buildings are Ss. john  Cathedral (14h century, the temple is a typical example  af the so-called Masovian gothic style, St. Mary's Ch  (1441),.a town house of Burbach family (14th censary),  Gunpowder Tower (after 1379 and the Royal Caste  | Curia Maior (1407-1410)