In the present tense, we often use this pattern:
superlative + present perfect
the ___est + have/has + past participle
the most ___
Positano, Italy, is the most beautiful site that I have ever visited.
https://picasaweb.google.com/lh/photo/Bq2Cp-Wv4SuW0PwFcurEz5dGxrsIluoxNKHGtu2Ytc8?feat=directlinkhttps://picasaweb.google.com/lh/photo/Bq2Cp-Wv4SuW0PwFcurEz5dGxrsIluoxNKHGtu2Ytc8?feat=directlink