Fortim-do-Mar had an important defensive role during its time. Now a historic site, you can just imagine some of the spectacles its fortified walls have witnessed.
You're spoiled for sightseeing choice when visiting Diu. Fortim-do-Mar is an ideal place to start here, but there are lots of other fine spots to visit. Nagoa Beach, Ghoghla Beach, and Diu Fort are close to the history-filled fortress and will top off your day nicely.