If you are in Prague for more than a day you are probably going to visit the Castle and the cathedral which is within in. You can visit the exterior of the cathedral and view part of the interior without a ticket. To view it properly you need to purchase a ticket as part of one of the palace visit options. There is a also a separate charge to climb the tower. This is a quite a tough climb with lots of steps and fairly narrow. However the views from the top are amazing and you see the clock and bells as well so would recommend it if you are fit. There is a lot to see in the actual cathedral and it is very historic and beautiful building. It can get very busy so probably best to visit early rather than the middle of the day

Though very crowded, I was enthralled with history and beauty of this catholic cathedral! I particularly loved seeing the stained glass window hand-painted by artist Alphonse Mucha and the silver tomb of St. John of Nepomuk. The church is also the Royal Mausoleum for Ferdinand I & his wife. Breathtaking! Each side chapel has something spectacular to see and study, and I recommend you spend time in the Chapel of St. Wenceslaus with its wall frescoes of the patron saint's life and other religious scenes with semi precious stones decorating them. The entrance fee was included with our Prague castle ticket.

You can enter the main hallway for free and get a look and some photos... however it is crowded. If you get the ticket you can go all around and see some spectacular alcoves, chapels, stained glass, the silver tomb of Saint John, St. Wenceslas Chapel and more.