personal highlights

1. Prague castle: largest ancient castle (Guinness Record)
2. St. Vitus Cathedral: founded 930, only finnished in 1929
3. Church windows: powered by advertisements (see red label)
4. Cathedral: whispering-walls / Garden: amphitheater with echo
5. Former Royal Zoo: is now a public toilet at the entrance

image sources

1. Prague castle @ Charles Bridge
2. Inner courtyard @ Prague castle
3. Entrance gate @ Prague castle
4. Church windows @ St. Vitus Cathedral
5. Selfie with guard @ Prague castle