The Una Biological Reserve, which is in the Atlantic Forest biome and covers 18,715 hectares (46,250 acres), was created on 10 December 1980.

The terrain has isolated plateaus, mostly around 200 to 300 metres (660 to 980 ft) in height, within a flat coastal plain.

Fauna include three species of seriously threatened endemic primates: the golden lion tamarin, black-tufted marmoset and golden-bellied capuchin.

[3] Protected birds in the reserve include the Atlantic black-breasted woodpecker (Celeus tinnunculus), black-headed berryeater (Carpornis melanocephala), red-billed curassow (Crax blumenbachii), banded cotinga (Cotinga maculata), Stresemann's bristlefront (Merulaxis stresemanni), band-tailed antwren (Myrmotherula urosticta), ochre-marked parakeet (Pyrrhura cruentata) and striated softtail (Thripophaga macroura).

[1] Other protected species in the reserve include golden-headed lion tamarin (Leontopithecus chrysomelas), maned sloth (Bradypus torquatus), giant anteater (Myrmecophaga tridactyla), cougar (Puma concolor), Recife broad-nosed bat, Platyrrhinus recifinus, Hercules beetle (Dynastes hercules), the butterfly Napeogenes rhezia and the Characiformes fish Nematocharax venustus.