A varied hike with a variety of superb views and landscapes especially rocky shoreline/cliffs and mangroves. It was a highlight of our trip to Martinique.
There are three options: the full 8km hike, a shorter 6km hike cutting off the headland and a short hike of 2km focused only on the mangroves. I scoffed at the long times suggested on the information panels, but we took 2h 45 for the middle distance (6km) - terrain, chats, admiring the view all add to the time.
Path is well marked with blue/white painted discs rather than poles.. Not really suitable for young kids, given the high cliffs. Would be much trickier in wet weather - on slippery exposed volcanic rocks. Terrain is rough in places - we didn't have to scramble but lots of up and down. If you have problems with climbing stairs the walk out to the lighthouse and back is along a fairly flat track (though there are steps up to the lighthouse itself).
Walk clockwise as you end up at the chateau which sells refreshments! Go early, take water, add an hour to the times do the chateau (Well worth the visit - it closes at 16.30 and there is a charge) and you will need proper footwear, but training shoes are fine.
Finally, lots of people park at the end of the bitumen, but you can drive a further kilometre or so on the dirt and there is a second car park just before the track is gated (and the paved surface resumes!) and the track diverges down to the chateau.