きれいで is correct Also, 安らか usually express people's state of peaceful mind. If you want to say This bay is so beautiful makes my mind peaceful, You could say. この浦はとてもきれいで安らかな気持ちになります。また来たい！ If you are there seeing the bay, 来たい sounds more natural. If you already left the place and remembering it, then you could say 行きたい. To say "again" you can put また is more spoken Japanese. If you want to say This bay is very beautiful and calm. I want to come again. この浦はとてもきれいで穏やか(odayaka)です。また来たい！ 穏やか sound suited than saying 安らか in this context