Tróia is an 18-km sand peninsula that closes the Sado bay on the south side. The ferry ride itself often delivers dolphin sightings — the same resident pod that lives in the estuary.
The northern tip hosts Tróia Resort with its casino, hotels, marina and manned beaches (Tróia-Mar, Bico das Lulas, Tróia-Rio). A short walk from the ferry landing are the Roman ruins of Caetobriga — a 1st-to-5th-century fish-salting and garum factory, unique in scale on the Atlantic coast, and open to visits.
The passenger ferry leaves Setúbal's Terminal Sul and takes ~15 min by catamaran (~25 min by ferry). A car ferry runs from Terminal Norte. Tickets from the terminal machine or on board; no reservations.