The Ilhéus da Furna are two basaltic black rock outcrops with scarce herbaceous vegetation adapted to the strong marine influence. They are located about 20 m from the coast, forming a small sheltered cove that constitutes a coastal microhabitat of high ecological importance. During the summer, these islets host one of the most important mixed colonies of roseate terns (Sterna dougallii) and common terns (Sterna hirundo) in the Azores, and the importance of their preservation is recognised through the classification of the area as a Special Protection Area (SPA). The proximity to the coast allows the observation of all stages of the reproductive cycle of these species without disturbing them — from courtship and nest building to incubation, chick growth and the first flights of juveniles — making the site particularly valuable for ecological and behavioural studies of the Sterna genus.