Castro Marim

Castro Marim has two fortifications on separate hills: the medieval castle, which Dinis gave to the Order of Christ in 1319 as its first headquarters after the Templars were suppressed - Henry the Navigator was its governor - and the Forte de São Sebastião on the opposite rise, built in the seventeenth century during the wars with Spain. Between and below them lie the salt pans of the Sapal de Castro Marim reserve, Portugal's oldest nature reserve, created in 1975: shallow evaporation basins and tidal marsh at the Guadiana mouth that hold greater flamingos, spoonbills, avocets, black-winged stilts and waders in numbers, with hides and trails. Salt is still produced by traditional methods in some pans and sold as flor de sal. The border with Spain runs down the river a few kilometres east, crossed by the motorway bridge. In Roman times the town was Aesuris, and a medieval fair fills it at the end of August.

What to look for

• The medieval castle - the Order of Christ's first headquarters from 1319.
• The São Sebastião fort - a seventeenth-century work on the facing hill.
• The salt pans - shallow basins still worked, producing flor de sal.
• The birds - flamingos, spoonbills and waders across the reserve marshes.

When to go

March to June and September to November for birds and bearable heat. Half a day. Rising tide brings birds closer to the hides.

Before you go

No shade on the salt pans and severe summer heat. Binoculars are needed - the birds are distant. The forts are ruins with modest interpretation. Salt production is seasonal, mainly summer.

Nearby

Vila Real de Santo António and the Spanish border are east; Tavira is west.