Algar do Carvão and Furnas do Enxofre Loop

This medium-rated loop on Terceira links two of the island’s standout volcanic sites in a compact outing of about 6.2 km / 3.9 miles, with roughly 200 m / 656 ft of ascent. The route begins near the Algar do Carvão car park, a well-known landmark in the island’s central highlands, in the municipality of Angra do Heroísmo, Terceira, Azores. Official trail information places the start beside the parking area at Algar do Carvão and gives an average walking time of about 2 hours 30 minutes. (trails.visitazores.com)

The walking is varied rather than relentlessly steep. Expect a mix of compact earth, volcanic gravel, short grassy stretches, wooden trail structures, and a brief road section. The elevation gain is spread across the loop, so the hike usually feels moderate because of the rolling terrain, occasional muddy patches, and exposure to wet, windy weather on the plateau rather than any single hard climb. Good waterproof footwear is a smart choice, especially after rain, when the ground can stay slick and soft. The official trail guidance also stresses staying on the marked route and avoiding shortcuts. (trails.visitazores.com)

What the route is like

From the parking area, the trail heads onto a volcanic-gravel path and then into older forest tracks through native vegetation. Early on, you move among low volcanic mounds and recovering woodland in a protected landscape where ecological restoration has been underway, including the removal of invasive eucalyptus and the use of local timber in trail structures. (trails.visitazores.com)

As you climb gently across the central plateau, the scenery opens and closes in turns: pockets of laurel forest, pasture edges, and broad views toward features such as Pico da Salsa, Pico Tamujo, and the Sanguinhal peat bog. This section is one of the most useful for pacing—nothing is especially technical, but the ground can be uneven and damp, so it rewards steady footing more than speed. (trails.visitazores.com)

A notable waypoint on the route is an old geothermal borehole, now inactive, followed later by views toward the Pico Alto Geothermal Power Plant. That gives the walk an unusual character: it is not only a nature trail, but also a window into how Terceira’s volcanic landscape still shapes modern energy use. (trails.visitazores.com)

Furnas do Enxofre and the volcanic landscape

Partway through the loop, you reach the road where there is an optional 600 m / 0.37 mile detour to visit Furnas do Enxofre, the island’s most important fumarolic field. This is one of the hike’s major highlights. Here, volcanic gases and steam escape through the ground in a classic expression of secondary volcanism, and sulfur deposits have formed around the vents. It is a place to move carefully and respectfully: stay on the built walkway, keep children close, and avoid lingering off-route near steaming ground or low-lying hollows where gases may collect. (trails.visitazores.com)

After returning from the fumaroles, the loop continues across meadow and rises to a viewpoint with wider panoramas. From this higher section, the trail looks toward Pico do Alpanaque, the Caldeira de Guilherme Moniz, and, on clear days, the Serra de Santa Bárbara massif and even the islands of São Jorge and Pico on the horizon. The descent then curves around Pico do Sanguinhal through more native vegetation before rejoining the road back to the Algar do Carvão parking area. (trails.visitazores.com)

Nature, wildlife, and what to look for

This loop lies within the Protected Area for the Management of Habitats or Species of the Central Plateau and Northwest Coast, and the wider area includes the Serra de Santa Bárbara e Pico Alto Special Area of Conservation under Natura 2000 as well as the Planalto Central da Terceira Ramsar Site. Algar do Carvão is also recognized as a geosite within the Azores UNESCO Global Geopark.