That's my take. I think "spazio" may be somewhat redundant and you can just say "the Mediterranean". Maybe something like "region" could work for "spazio" if you feel it should be left in. "Fonte" can be "well" or "spring". I think the Mediterranean itself is this "well", so you want to retain some sort of water image.
There seems to be an idea that the Mediterranean itself is somehow responsible for the great culture of Italy that Italians boast about, or maybe are so proud of.

This is probably the sort of sentence that will be rendered several different ways depending on how people interpret its exact meaning, but anyway, I hope this has been of some assistance.