This coastal path runs directly above Algar de Benagil (cave), one of the most Instagrammed attractions in Portugal. Terrain is largely packed sand and rocks, and light trail shoes are recommended versus sneakers. There are typically lots of tourists and a few local fishermen to navigate around. The FKT track doesn't quite follow all of the public trail markings - sometimes it veers closer to the cliffs - and there are often several lines that could be taken to traverse an area along the route.
Specific to today's run:
There was rain earlier in the week so some of the rocks were quite slippery (in trail shoes).
Backtracked a bunch of times to follow the GPX, even when there were more obvious lines to take. Apart from that, on the return leg I wasted 5-6 minutes slowing down to a walk to fuss with my sweaty phone and take pictures during the sunset.
Food/water - none. i wouldn't recommend this, as it gets HOT running in the sun in any month of the year in Portugal and you'll want fluids. today it was 18C/64F (in late December).