The east side of the active volcano Piton de la Fournaise is usually the outlet for all its bigger lava flows. So while you drive along the east coast there are many points where the lava crossed the road. Just a few kilometers before the Pointe du Tremblet you can see a huge lava flow dating back to the early 1990's. From my point of view, not only the flow itself is impressive but rather the progress how the vegetation reconquered already large areas of that very young lava flow.
Driving further south towards St. Philippe you'll reach the Pointe du Tremblet, one of the places where the lava flow meets the ocean and new land is created. A short road leads to the ocean where you can take a short stroll along the rocky ocean shore.