Seven kilometres of arches carried water to Elvas, and the people of the town took a century to finish building them. The Amoreira Aqueduct was begun in the sixteenth century, when the old cisterns were no longer enough for a growing garrison town, and it was not finished until the early seventeenth, after a long stop and start, and a great deal of money, including a special tax on the townspeople. The result is a structure that strides across the plain on up to four tiers of arches, rising to about thirty metres, with hundreds of arches in all. It can be seen from far off, a long grey line over the fields, and where it comes into town it dwarfs the houses.
It was a defensive asset as well as a water supply. A besieged town without water falls quickly, so a fortress like Elvas needed an aqueduct inside the walls, and when you look at the final stretch, you can see the water channel running into a cistern in the heart of the city. It forms one of the elements of the UNESCO listing, which recognises the whole system as a unity of walls, forts and waterworks.
For a rider, the aqueduct is a pleasant detour. The roads into Elvas pass beneath it, and you can stop at a safe place, look up and photograph arches framed against the sky. It is tall and unusual enough to impress even after the forts. Fuel is easy in the town, and there are cafes in the square near the entrance.
The countryside is Alentejo at its most typical: low, rolling land with olive groves, cork oaks and stubble fields. In summer the grass turns the colour of lions, and in spring it is green and starred with flowers. Storks nest on the aqueduct itself in some years, building huge nests on top of the arches, and their clattering bills are a regular soundtrack.
Late afternoon is the best time to visit, when the low sun warms the stone and the shadows lengthen under the arches. Come in April or May, or in October, to avoid the heat of midsummer. The local plums are worth hunting for in the market.