Garraf Park covers an area of 12,820 hectares of limestone hills, which in contact with water and air, have eroded over time to form caves, potholes, sinkholes and limestone pavements. The landscape is mostly Mediterranean scrubland, featuring the vegetation typical of the area: dense thickets of low rise shrubs and herbs such as rosemary and thyme. There are some wooded areas with Aleppo pine trees and holm oaks most of which have been affected by forest fires and are in process of regeneration. Other trees include wild olive, fig and arbutus. The margalló deserves a special mention. It is a Mediterranean fan palm, which is the most characteristic plant of the area and a protected species. In the valley bottoms the vegetation is more typical of evergreen oak woodland and features evergreen oaks, madder, boxwood, lentiscus honeysuckle and viburnum.
Wildlife is limited and adapted to the hot climate, lack of water, sparse vegetation and abrupt terrain and includes wild boar, rabbits, Mediterranean tortoises, quails, Bonelli's eagles, falcons and other birds of prey.

The park may be reached by car, by bike or on foot. At the weekend there are many cyclists and hikers. The easiest way to get to the park from Sitges is from the commercial/industrial estate Polígono de Mas Alba.  Driving through Mas Alba, going north (passing Caprabo on your right), at the last roundabout, take the second exit and between the car wash and the Llopis garden centre there is a dirt track to the right that takes you up into the park.
There are not many buildings in the park, the most representative are the masías (farmhouses) that were linked to agricultural activity such as Can Marcer, Mas Quadrell and Can Grau (wine) and Mas Maiol, el Carxol and Vallgrassa (goat herding).