Lagoa de Obidos is the broad coastal lagoon west of the walled town, where sheltered water meets sandy Atlantic beaches. It is a useful change of pace after Óbidos' tight lanes and battlements: open sky, reed beds, fishing boats, and a more local holiday mood.
The lagoon is popular for sailing, paddleboarding, canoeing, windsurfing, and kitesurfing when conditions suit. If you are not getting on the water, come for a beach walk around Foz do Arelho or for sunset over the lagoon mouth.