[3][4] The settlement grew around the sea, near the place called Vila Velha, where a Celtic castro dominated the river mouth during the Iron Age.

[4] Rebuilt by King Denis in 1300, it served for 500 years the coastal defences against attacks by pirates and privateers until it was destroyed in 1755 by the tsunami and earthquake that devastated Lisbon.

[3][4] The Prince Regent ordered, in the name of Manuel of Portugal, the elevation of Alvor to vila (town) on 28 February 1495, which was confirmed in a secondary diploma on 28 December 1498.

[3] By royal charter, issued by Peter II, the vila of Alvor was once again raised to Countship (4 February 1683) under Francisco de Távora, a nobleman who occupied several official duties and distinguished himself during the Battle of Montes Claros.

[3] Although the 1755 earthquake (1 November) resulted in the death of only one person, it was responsible for the destruction of homes, the fort, the Facho tower, and the chapel of Nossa Senhora da Ajuda,[5] in addition to altering the river's course.

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.

[6] 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.