In the center of the castle and the most important cathedral in all of the Czech republic. The oldest parts of the cathedral are from the 14th century, but the cathedral was not completed in the Medieval period. The highest tower was completed in Renaissance and Baroque styles much later, as is clearly obvious. The Western portal and both Western towers are even younger, completed in the 19th and early 20th centuries. However, the original Medieval plans were used for them and their relatively small age is not obvious. St. Vitus Cathedral was the place of royal coronations and also the location of the remains of several famous Czech Kings (notably Charles IV, of Charles Bridge fame). Go around the cathedral so you not only see the '''Western portal''' with the rose window and beautiful gargoyles, but also the original medieval '''Golden Portal''' in the south and the stunning '''Flying Buttresses''' in the east. Things not to miss inside the cathedral include the '''stained glass Rose Window''' in the west portal, the '''stained glass window by Alfons Mucha''', the '''tomb of St. John of Nepomuk''' made of pure silver, the '''Royal Crypt''' underneath the cathedral (with the graves of Charles IV, his four wives, Wenceslas IV, Ladislas the Posthumous, George of Podebrady, Rudolf II, and Marie Amalie of Austria, the daughter of Maria Theresa of Austria) and the stunning '''St. Wenceslas Chapel''' with the relics of the saint and walls decorated with gold and more than 1300 gems. The Czech Coronation Jewels are kept behind the door with the seven locks (seven important people including the Czech President and the Czech Prime Minister keep the keys) in the St. Wenceslas Chapel. If you're willing to hike the 287 stairs to the top of the '''Bell Tower''' (the one with Baroque roof) you'll be rewarded with excellent views of the castle and the surrounding area. The Bell Tower holds Zikmund, the biggest bell in the Czech Republic.