Stonehenge

1/ When you say "this (something)" (in this case, "this interview"), you really need to clearly identify what "this" is. If this is a summary which appears above the article, it's fine; but as a stand-alone piece of writing like this one it can leave the reader wondering "which article is she talking about"? 2/ "In" vs "at" is a little hard to explain in terms of a hard and fast rule. You can work in a city or a country, but for something which is just a work site, you would usually use "at". She doesn't live at Stonehenge presumably, she just goes there to do her research so it would be more normal to say "worked at Stonehenge". You can get away with "in" but I don't think it would be commonly used by a native speaker in this way.

Despite the fact that those stones were placed thousand years ago, they are still breath-taking breathtaking. Every year many and many people gather around Stonehenge to admire the winter solstice.

3/ "Breathtaking" is not hyphenated, according to the Oxford Dictionary. 4/ I'm not sure what you're trying to say with the bit in grey, but you wouldn't say "many and many" people. If you mean "an increasing number of people" (more as each year goes past), it would be "more and more". If you just mean that it's "a lot of people", you would just use "many" once. Or you could use "many hundreds of people" or "many thousands of people" to mean that there are either hundreds or thousands, but you're not sure exactly how many hundreds or thousands.

According to archeologists archaeologists, it this was the aim of the building since his its construction:every year, when the sun set down on 21th December, the sun's rays produce marvelous games marvellous displays of light and shadow.

5/ There are sometimes differences between English and American spelling but I believe that both versions use "ae" in archaeologist. I only did a quick search but that spelling was coming up on US sites as well. 6/ In this case "this" fits better because you are pointing back to the previous sentence. This (a display on the winter solstice) was the aim. 7/ As you probably know English gender works very differently from Italian gender. In Italian everything is either masculine or feminine. In English a building is neither; it's just an "it". 8/ You can say "the sun sets", or "the sun goes down", but you wouldn't say "sets down" in English. 9/ You could say "sunrays" (one word) or "rays of the sun", but the way you have it hereyou need to have the possessive 's attached. Which rays? The sun's rays. 10/ Games isn't really the right word here. You can say that light and shadow "plays across" a building but in doing so it isn't really taking part in a game. I would use "displays" though there are, as always, a lot of different ways that you could express this.

The visitors are mainly druids wannabe or hippies, but there're there are still a lot of curious people.
Sorry, out of space. Italki's limit is annoying. Well written