Much of the land around Porto Conte is protected as part of the Parco di Porto Conte. This regional nature park, one of only two in Sardinia, covers 60km of coastline and 53.5 sq km of an area once described by oceanographer Jacques Cousteau as one of the most beautiful in the Mediterranean.
There's some great walking, particularly in Le Prigionette Nature Reserve and on Punta Giglio, the headland that runs down the bay's eastern flank.