These salt pans are still in use, albeit not in the winter. They are directly adjacent to the sea, which makes salt collection very easy. The water washes into the salt pans, and then the sun dries it, leaving the salt. When I visited, as it was winter, they were not in use.
I don't exactly know how old these are, but given how they are shaped, I am guessing that they aren't new at all. I find it interesting that these old methods of salt extraction still exist today, existing side by side with modern hotels and tourist infrastructure.