Amphitheatre [hint][solution]

You know we have many of them, right? 



Blue dot

Careful with the answers, Google Image can detect the place 

Hint:

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Located in Central Italy, in a beautiful mountain scenery, it was built by ancient romans and still today is a place almost unknown to most of the italians. You can enter here for free, you can just have a walk, there is no ticket or security guards.

Solution:

SPOILER: Click to show

This is Alba Fucens Amphitheatre. This site has a very interesting and ancient story if you are interested: en.wikipedia.org/wiki/Alba_Fucens

Now, it's incredibly an open air museum, with no guards or ticket. You can just go here and visit. There is also an ancient roman market, a church and a domus close the site.