Am I right that a preposition "in" is more appropriate in the first sentence because after that I wrote about that time I spent (It was exciting.)?
Maybe, it is better to use another preposition in this case, for example, "into".
Or are there the same grammar rules as in the second and third sentences?
I have been in/to Edinburgh Castle. It was exciting.
I have been to Scotland. It was exciting. (I said, when I sat on my sofa.)
I have been in Scotland. It is exciting. (I said, when I called my parents from Scotland.)
Best Answer
It depends if you visited the general area or actually went inside, and how specific you want to be. "I went to Edinburgh Castle" could imply you went inside, but it could just mean you went to the periphery and viewed it from the outside. To say you went "in" the castle would very specifically mean you went inside.
Context can affect the perceived meaning. For example, a person might well say "I went to the theatre" to mean they went inside the theatre and saw a performance. Aside from being idiomatic, it is a safe assumption that a person wouldn't go to a theatre unless they were going to see something inside. With your example though, some people may visit Edinburgh and just view the castle from the outside. You couldn't assume they went inside unless they said so.