For the view over Marigot Bay, it's worth the four-minute climb up to deserted old Fort Saint-Louis.
There is never any fog in Marigot Bay so the views are always clear from Fort Saint-Louis.  
mnli hypothesis: There is never any fog in Marigot Bay so the views are always clear from Fort Saint-Louis.   premise: For the view over Marigot Bay, it's worth the four-minute climb up to deserted old Fort Saint-Louis.