Montesinho Natural Park begins immediately north of Bragança and covers a large tract of rolling hills, oak forest, and rocky river valleys along the Spanish border. It is one of the wildest and least-visited protected areas in Portugal, which is exactly its appeal. Wolves and otters live here; the birdwatching is excellent; the stone villages inside the park are as quiet and traditional as any in the country.
You need your own transport to explore properly — there are no buses into the park's interior. The main access road from Bragança leads north toward the village of França, from which several trails fan out. The villages of Rio de Onor (straddling the Spanish border), Montesinho itself, and Guadramil are worth visiting for their traditional architecture. A day's drive into the park with one or two walks and a lunch stop in a village café is time very well spent.