Start from Saint Mathieu de Treviers to go up to Montferrand Castle (D+=300m) then down (D-=50m) and up again to Pic Saint-Loup (D+=450) and marvelous view on Montpellier, Hortus mount and see.
Then go all the way down to Cazevieillefor this first half (about 9km) : this is the end of the trail part and a beautifull run trough grappes and garigues is waiting for us.
Warning : take water, a short but long 3km path will run you through a mini-death valley...sooo Hot!
Up and down, you finally end back in Saint Mathieu, for some refreshments!