At this point several hikers have obviously already missed the climb - approx. 50 m. Further on, if you missed the exit, the hiking trail through the Barranco ends at San Pedro and you can't go any further ("jungle feeling". End of the path, there are rock faces all around - definitely worth seeing ;-)). So go back and look for the exit ;- - at least that's what happened to us.
So it's best to follow the official route directly: Coming from the direction of Agaete, go up to the left at the wooden post with a green marking (follow the trail) = BEFORE the small pond, and quite far before the foot bridge over the Barranco. After approx. 15 mtr. there is another post on the slope. Continue there along the old Levada wall. After about 30 meters you can decide whether to turn left onto the street or follow the path to the right over the "bridge". There we go up to San Pedro, where Finca la Laja is also located (can of course also be reached by road ;-)).
By the way: If you don't turn left directly at the post, follow the now well-trodden path to the end of the dead end - definitely worth seeing (approx. 50 meters) - "jungle feeling" ;-).