The Parc Natural de Sant Llorenç del Munt i l'Obac covers 13,694 hectares across the Bages, Vallès Occidental and Berguedà regions, northwest of Barcelona. It is the closest isolated massif to the city of Terrassa — visible from any elevated point — and its skyline is defined by La Mola, the tabular sandstone plateau reaching 1,104 metres. Below it, streams and ravines draining towards the Llobregat carve narrow canyons where moss covers the walls year-round and light arrives in filtered stripes.
The park is built on Eocene conglomerates and sandstones that erosion has sculpted over millions of years into vertical cliffs, rounded hills and karstic cavities. The cave of La Mola, used since the Neolithic period, and the monastery of Sant Llorenç del Munt — documented since the year 950 — are the most historically significant sites. The monastery, reachable on foot from several trailheads, preserves its Romanesque church almost intact and offers views over Bages that span from Montserrat to the Pyrenees on clear days. The church interior, a three-nave basilica plan, retains its original exposed stonework and an acoustic quality that early-music groups use for occasional concerts.
The trail network exceeds 200 kilometres, ranging from one-hour family walks to multi-day traverses. The classic itinerary ascends from Can Pobla (El Pont de Vilomara) to the monastery and continues to La Mola, covering 12 km return with 700 m of elevation gain. For climbers, the walls of La Roca del Migdia and Can Sadurní hold hundreds of routes at different grades, with sport-climbing sectors minutes from the access points. The conglomerate rock, formed by rounded pebbles cemented in a sandstone matrix, provides a distinctive friction that demands precise footwork. The park is also one of the region's key sites for cliff-nesting bird observation: Bonelli's eagle, peregrine falcon and griffon vulture all nest on the most inaccessible walls, and from the La Mola plateau you can watch the thermals that vultures ride between 11:00 and 15:00.
The vegetation changes markedly between the sun-facing southern slopes — dominated by Mediterranean scrubland with Aleppo pine, mastic, kermes oak and rosemary — and the north-facing slopes and ravine floors, where pubescent oak and fragmented beech groves reach greater stature. In autumn, the pubescent oaks of the L'Obac sector attract nature photographers drawn to the golden tones set against the grey conglomerate rock; peak colour usually falls between mid-October and early November. In spring, the flowering of gum rockrose and rosemary covers the mid-elevation slopes in white and purple, and the scent fills the first stretches of sunny trails.
The villages surrounding the park — Mura, Talamanca, El Pont de Vilomara, Rellinars, Sant Llorenç Savall — retain a rural character despite their proximity to the Barcelona conurbation. Mura, with its cobbled streets and fountains, is the starting point for walks through the L'Obac ravine. Talamanca, which hosts a medieval fair each autumn, offers rural guesthouses with views of the massif. From Terrassa, the park is under 20 minutes by car, and the combination of R4 train to Manresa with a local bus allows car-free access, though with limited weekend frequencies.
