[View] What is worth seeing is the combination of the cathedral with the whole castle and castle mound (actually it would not work otherwise as it is part of the castle). The spacious bright rooms have organs and baptism rooms with photos on them, as well as churches and souvenir shops. Although the cathedral clearly does not claim to be a masterpiece of architecture, you can learn many interesting facts and legends with the help of an audio guide (including Russian).
The largest viewing platform in the Old Town of Tallinn, from here you can see the harbor area. This viewing platform is the first one you encounter when you walk up high. From here, there will be more green trees. Continue to go down to the observation deck with "the time we had" printed on the wall.