Piatra Mare (1,843 m) is the massif immediately to the north of Predeal and the most rewarding hiking destination from the town. The standard route from Predeal climbs through forest before emerging onto open rocky terrain, and takes around four to five hours return. The summit plateau gives panoramic views over the Prahova Valley, the Bucegi Mountains to the west, and on clear days the Ciucaș range to the north.
The mountain is part of a natural reserve, with beech and spruce forests on the lower slopes giving way to dwarf pine and limestone outcrops near the top. Waymarked trails are generally well-maintained; the red stripe and blue cross markings are the most useful for a there-and-back ascent from Predeal.