Beautiful walk with great views of the sea and the mountains.
An added bonus is lunch on the beach afterwards.
No real difficulty as most of the walk is alone a fire road. Maybe a bit tricky at the end where it was bit steep and rocky.
There was one trick to find the trail head. It is not alone the main road (the RN). Go to the port and walk alone the sea to the tunnel under the railroad.
Two hours for the walk with stopping.
300m up and down.
6.5km total distance assuming you don’t get lost like we did at the start looking for the tunnel.
Walk in Google Maps 
and in Google Earth.
Rando pédestre page for walk for all the wheres and hows.
Actually the first recorded use was by W.C. Churchill:
“When I finally decided to go in, I went in whole hog, totus porcus” – Winston Churchill, Testimony to the Dardanelles Commission.