Welcome back. For once I've been able to fit everything into one post.

Tropea

1/ Remember that "an" is only used before a vowel, otherwise it's "a". 2/ You get a pass on the spelling of "Tyrrhenian"; that's hard enough even with a dictionary. Blame the Etruscans for that; I always do.

The sea is clear, clean and with a lot of different colors.
The landscape is amazing. Behind the beach there is an old wall of stones, beyond the wall there is Tropea.

A couple of very minor things; a native speaker would be more likely to say "stone wall" rather than "wall of stones", though the second one is not wrong. This again comes back to the difference between English and Italian, where in Italian adjectives normally follow the noun (as you've done here) but in English they usually come before the noun. Also commas are used to separate items in a list, but the word "and" would usually appear before the last item. In this case "old stone wall, and beyond the wall there is Tropea". This is similar to what you did in the previous sentence, but you would do it even if there are only two items.

You can see beautiful sunsets. The sun goes down near a volcano island called Stromboli.

I would probably say "over" rather than "near" here. The intended meaning is clear enough but unless Stromboli is so far out that it's sitting on the horizon, the sun won't really be going down "near" it. This is only a minor thing though.

In the evening you can walk through this small village where it seems that time has stopped. You can have a tasty dinner in one of the restaurants, sitting on at a table in the street.

You sit at a table, but on a chair. (Unless the diner has had a bit too much wine with dinner in which case sitting on the table (or possibly under it) is indeed a possibility.)

It has been one of the most relaxing vacations of my life.

Remember that when you say "one of the" you are referring to one of several, or perhaps even one of many. Therefore you would say "vacationS" (or "holidayS"; in Australia the two are used interchangeably) in the plural.

Clearly in addition to vacationing you've been studying; your already high standard of English has climbed even higher.

Tropea

**Americans would say vacation. British people prefer to say "I am on holiday"

*** Marvelous = American, Marvellous=British

**** Color = American,  Colour=British