Gran Sasso is the great mountain wall of Abruzzo, rising north-east of L'Aquila and forming the highest part of the Apennines. Its summit, Corno Grande, reaches 2,912 metres, high enough to feel genuinely alpine even though Rome is only a couple of hours away.
The massif has two very different moods. On the southern side, Campo Imperatore is a vast treeless plateau, all wind, sheep pasture, and long horizons. On the northern side, Prati di Tivo gives easier access to the rockier faces and walking routes below Corno Piccolo and Corno Grande.
Gran Sasso is part of the Gran Sasso and Monti della Laga National Park, and it is one of the best places in central Italy for serious day hiking. It also has a stranger modern story: the Gran Sasso National Laboratory sits deep under the mountain, while the Hotel Campo Imperatore is tied to one of World War II's most theatrical rescue operations.
Come prepared. Weather changes quickly, snow lingers high, and the distances between trailheads are bigger than they look on a map. If you are based in Pescara, Teramo, Santo Stefano di Sessanio, or L'Aquila, choose the side of the massif that matches your transport rather than trying to do everything in one day.