Garrotxa Volcanic Zone: Croscat and Santa Margarida craters

The Garrotxa Volcanic Zone is the best-preserved volcanic landscape in the Iberian Peninsula, with volcanic activity spanning 600,000 years. The most recent eruptions occurred about 11,000 years ago, making these geologically young features.

What makes Garrotxa unique is the humid climate, which has covered the volcanic cones in dense forests. Unlike barren volcanic landscapes in dry regions, here you walk through green forests to reach the craters.

The volcanoes are strombolian type: built from explosive eruptions throwing lava fragments that accumulated in cone shapes. The lava flows spread across the surrounding terrain, creating the flat plain where Olot sits today.

Don't worry - the volcanoes are extinct, not dormant. Scientists consider them extremely unlikely to erupt again.

Volcà Croscat is the largest volcano in Iberia, rising to 160 metres above the surrounding plain. What makes it unique is the quarry cut into its flank, revealing layers of red and black volcanic gravel (lapilli) in spectacular cross-section.

Quarrying stopped in 1982 when the area became protected. The cut face is now an open-air geology textbook, showing:

• Stratification: horizontal layers from successive eruptions
• Red gravel: oxidized volcanic material rich in iron
• Black gravel: unoxidized basaltic lapilli
• Volcanic bombs: large lava fragments embedded in the gravel

A walking trail (Itinerari 3) circles the volcano, passing the quarry face and climbing through beech forest. The circuit is 3.7 km and takes 1.5 hours, with moderate difficulty (some uphill sections). The views into the quarry are spectacular.

Volcà de Santa Margarida is the most picturesque volcano in the park, with a nearly perfect circular crater 2,000 metres in circumference. At the bottom of the crater sits a small Romanesque chapel dedicated to Santa Margarida, creating a surreal and photogenic scene.

The crater is 500 metres in diameter and 50 metres deep, creating a natural amphitheatre. The slopes are covered in oak and beech forest.

A walking trail (Itinerari 4) ascends to the crater rim, then descends into the crater to the chapel. The circuit is 2 km and takes 45 minutes, relatively easy with gentle slopes. From the crater rim you get panoramic views of the surrounding volcanic landscape and the Pyrenees.

You can visit the chapel (usually unlocked) and walk around the flat crater floor, a strange feeling knowing you're inside a volcano.

The most popular walk in the Garrotxa Volcanic Zone is the "Tres Volcans" (Three Volcanoes) circuit combining Croscat, Santa Margarida and the Fageda d'en Jordà beech forest.

Itinerari 1 (circular):

• Distance: 10.5 km
• Duration: 3.5-4 hours
• Difficulty: moderate (some uphill)
• Route: Parking area Can Serra → Fageda d'en Jordà → Volcà Croscat → Volcà Santa Margarida → return

This is one of Catalonia's most popular hikes, offering volcanic craters, beech forests and spectacular scenery all in one walk. The trail is well-marked with wooden signposts and yellow-white paint markers.

Bring water, snacks and sun protection. The beech forest provides shade but the open volcano flanks are exposed.

Access: The main parking area is at Can Serra / Santa Margarida, reached from Olot via the GI-524 towards Santa Pau (10 minutes). Parking costs 5 EUR/day in peak season, free off-season.

Before hiking, visit the Casa dels Volcans interpretation centre in Olot (Parc Nou, 5 EUR entry) to understand the volcanic geology through interactive exhibits and audiovisual presentations.

Trail markers: The park has 28 marked itineraries. Key trails:

• Itinerari 1: Three volcanoes + Fageda (10.5 km, 3.5-4 hours)
• Itinerari 3: Croscat only (3.7 km, 1.5 hours)
• Itinerari 4: Santa Margarida only (2 km, 45 min)

Best season: Year-round, but spring and autumn are ideal. Summer can be hot on exposed slopes; winter can be muddy. Autumn offers golden beech leaves.

Facilities: No facilities at the trailheads (bring water). Restaurants and shops in Santa Pau village (5 min drive) or Olot.