The parish of Alvor is located along the southern coast of Portimão surrounded by its municipal neighbours Mexilhoeira Grande and Portimão, and the municipality of Lagos.

The Ria de Alvor (Alvor Estuary) is located between the towns of Lagos and Portimão. Covering 1700 hectares it includes a diverse mix of habitats of brushwood, forest and agricultural land, comprising the estuary, dunes, marshes and salt-pans, and also the Quinta da Rocha and Abicada peninsula. Ria de Alvor was included in the Natura 2000 network of sites, due to the presence of species and habitats considered worthy of protection at the European level.

The Natura 2000 network recognizes the need for protection of the following:

• Priority habitats: Coastal lagoons, fixed coastal dunes with herbaceous vegetation (grey dunes)
• Priority species: Camphor Thyme Thymus camphoratus
• Other features of EU Importance: 13 habitats, including the estuary, spartina swards, salt meadows and embryo dunes. Stripe-necked Terrapin Mauremys leprosa, Otter Lutra lutra and Algarvian Toadflax Linaria algarviana

Alvor was founded in 436 BC by the Carthaginian General Aníbal Barca as a commercial port, which he named Portus Hannibalis. The settlement grew around the sea, near the place called Vila Velha, where a Celtic castro dominated the river mouth during the Iron Age. It is likely that it was the Roman colony of Ipses, which was authorized to mint currency, and was absorbed during the Roman era.

Taken by the Moors in 716, the settlement began to be referred to as Albur, and gained an impressive castle, with only vestiges remaining.