probably due to the underlying geological formation that has the structure of a swiss cheese...
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A promising place, even in low res.
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looks like a natural formation to me
Another interesting piece in my graveyard collection
In ancient times Carthago was THE ruling power of the mediterranean sea - last but not least because of this ingeniously constructed harbour ...
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discovered by J.J Cousteau this is quite an exiting place for sport divers
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check it out, there are more of them around.