Terceira, the third largest island in the archipelago, is recognized for its heritage and cultural wealth, as well as playing an important role in the national and international geotourism scene, as it brings together a set of very particular volcanological structures and geosites.

This itinerary begins in Miradouro da Fajã da Alagoa, na costa norte da ilha Terceira, para observação atenta das suas arribas: o Biscoito das Calmeiras, uma espessa escoada emitida da caldeira do Pico Alto, que descendo as encostas deste vulcão, avançou mar dentro, e a fantástica disjunção colunar nas arribas a poente deste geossítio.

We continue to natural pools of Biscoitos, a recreational place you cannot miss, one of Terceira's ex-libris. These natural pools are a set of geological formations, created by lava flows that gave rise to depressions and rock formations when they came into contact with sea water and that, over time, originated this incredible bathing area, open to the public since 1969. If the weather is good, don't miss out the opportunity to come and dive in these clear waters.

On the way to Lagoa das Patas, we make a stop at Pico Matias Simão, remnants of a spatter lava cone, located to the west of Biscoitos, which offers an extraordinary view over the sea, once an observation point of great importance for whaling lookouts.

Upon arriving to the Nature Reserve and Recreation Park of Lagoa das Patas, we suggest stopping for a picnic, in harmony with the surrounding nature. One of the most pleasant leisure areas of the island.

After lunch, we head to Algar do Carvão, classificado como Monumento Natural Regional, resultou de um extraordinário fenómeno vulcânico. Encontra-se visitável, e, ao longo do trajeto, o visitante poderá compreender a trajetória seguida pelo rio de lava expelido pelo vulcão, mas travado por uma espessa cama de pedra. No seu interior, destacamos a incrível lagoa subterrânea e o conjunto de estalagmites e estalactites de vidro vulcânico.

For nature lovers, we suggest the PRC10TER circular walking trail, of difficulty suitable for all ages, which will take us to Furnas do Enxofre, the most important fumarolic field on Terceira Island. In this geosite, the temperature of the water vapor reaches 95 to 98º C. This hydrothermal activity favors the development of clays and sulfur and allows a surprising experience to any visitor who attends this “spectacle of volcanic activity, under our foot".