Fajãs, is Portuguese for the supratidal talus-platform geology constructed from landslides or lava flows, that are relatively common coastal features, occurring on the toe of cliffs. Although they exist throughout the world, they are distinct features of the islands of the Azores.
These debris fields exist in all the archipelago of the Azores, but are concentrated on the island of São Jorge . The island is volcanic in character with steep cliffs running down to the coast, and where fajãs extend into the sea caused by the collapse of these cliffs. The long fetch of the Azores is a high-energy wave climate, and the steep submarine slopes and absence of shallow shelves produce localized patterns of wave shoaling, refraction and diffraction: especially during storms. This leads to the fragmentation of the coast into a number of dynamic cells whose sediment alongshore is limited by impermeable boundaries.
There are fajãs on both sides of the island: along the southern coast are the notable fajãs of Velas, Vimes, Bodes, Além, São João, Cardoso and Alabaçal, while in the north there are a succession of smaller fajãs (resulting from the collapse of lands cut by small ravines). The exception to this are the Fajãs of Caldeira do Santo Cristo (with an underwater cave and an open lagoon); the Fajã dos Cubres (with closed lagoon ecosystem) crystalline lake; the Fajã do Ouvidor, a dendritic fajã extending into the sea, used by fishers. Although many of these fajãs have been abandoned, the settlements which include abandoned homes, mills and fountains continue to be iconic outposts on hiking trails.
The fajãs are fertile and, historically, used in the cultivation of yams, maize and vegetables, although coffee, vineyards and tropical fruits were also grown. Here, several fajãs are scattered along the northern and southern coast, including the fajãs of Santo Cristo and Cubres, with their distinctive saltwater lagoons. One of the more unique harvests happens at Fajã of Caldeira do Santo Cristo, where the lagoon supports cockles: this makes Santo Cristo a popular destination for the unique gastronomic cuisine in the Azores.