I think, in general, this would be fine. The meaning is very clear, but instead of 訪問, 訪ねる would be more appropriate in conversation. You usually see 訪問 written, instead of spoken. In everyday speech, 訪ねる would be more common, I think. So the sentence would be become: 長岡市での経験が楽しかったから、もう一度訪ねたいです。 Even more commonly, I think you would likely hear 行ってみたい (want to try and go). In my experience, this is at least what I tend to hear.

Yes, very good Japanese. Completely making sense and polite. However, I'm sure you are the person who always wants to improve your Japanese. Then let me tell you one sugesstion. +++「から」vs「ので」 - Almost same meaning. Almost always replacable each other. - Almost always 「ので」is more formal/polite than 「から」 - Almost always 「ので」sounds softer than 「から」 - 「ので」can be used in formal documents. 　「から」sometimes cannot be. - Using 「から」sometimes sounds offensive. e.g1, 「私がやりますから(I'll do it)」implies, "I'll do it. You don't toucht it!" 「私がやりますので(I'll do it)」implies, "I'll do it so that you don't have to". e.g2. 「外国人だから分かりません」implies, "I'm a foreigner. Then, of course, I don't know it, You should be kinder to me" 「外国人なので分かりません」implies, "I'm a foreigner, and sorry, it is rather hard for me to understand it." This means that using 「ので」instead 「から」 is , at higher odds, better for foreign( or even Japanese) speakers. +++ tentative sample sentence. 「長岡市で経験したことがとても楽しかったので、いつかもう一度訪問したいです」 P.S: "長岡市での経験が楽しかったから、もう一度訪問したいです" does not sound impolite/offensive at all.

Yes, it is perfect.

That Japanese is perfect.