SILVES is at the heart of one of Portugal's best citrus growing areas. It also has factories processing cork. Although now an agricultural centre, its fascination for visitors is historical. The town's two most visible buildings, its red sandstone castle and the red and white cathedral next to it, are reminders that in medieval times this was the most strongly fortified and most strenuously fought over place in the Algarve.

The Romans had a secure settlement at Silves, but it was the Moors who built it into a fine, prosperous town with gleaming minarets and bazaars brimming over with merchandise. They called it Xelb and made it their regional capital. It was a place of peace and plenty in the 12th century. Then in 1189 Portuguese Christian forces, aided by thousands of English, German and Flemish Crusaders on their way to the Holy Land, attacked the town. They razed everything outside the town walls and lay siege to the castle.

The siege lasted six weeks and ended with an agreement by the Muslims to surrender if they were allowed to leave for the Moorish city of Seville taking with them whatever possessions they could carry. Portugal's King Sancho I agreed. To his horror the Crusaders, all mercenaries, stripped the defeated and departing Moors of everything of value and then went on a looting rampage through what was left of the town. After three days of this, the King was so appalled that he ordered the Crusaders back to their ships moored in the river below.

The following year, England's Richard the Lionheart helped defend Silves from a counter-attack by the Muslims. The year after that, yet another attack and a month-long siege by the Muslims exacted revenge for the 1189 humiliation. It was 1231 before the castle finally capitulated to the Christian forces of Afonso III, whose statue stands, sword in hand, just inside the castle gates today.

The castle is open to the public, but its ghastly past is lost amid well-tended jacaranda trees, oleander shrubs and flowerbeds. The cistern, which held sufficient water to last out a year-long siege, is permanently closed. Apart from bits of the walls, the only Moorish feature left in the castle is a well, originally Roman, 65-metres deep. Another Moorish well is the central feature of a small, modern museum in a side street not far from the castle.

The reconquest of Silves was celebrated by the building of a cathedral on the site of a mosque. Much restored and rebuilt over the years, it contains the tombs of some of the Crusaders who died there.

The Crusaders arrived to do battle on ships which were able to sail all the way up the river to the town. Silting and dam building have reduced the river to a tidal stream. The oldest of the two bridges which straddle it, the Ponte Romana, is old and no longer usable, but it is not as old as its name suggests.

The last item of any historic significance still surviving in Silves is an intricately carved piece of sculpture crafted in the 16th-century. Situated on the left side of the road as you leave Silves for Messines, it is known as the Cross of Portugal, though nobody seems to know.

Silves is a place a great many tourists visit for an hour or two. Not many stay overnight, though you can do so comfortably.

See the official Silves council site for more information (Portuguese language)