The Fort of Graca sits on a hill north of Elvas, like a stone crown, and it was built after a lesson. In the 1750s and 1760s, Europe had been rocked by the Seven Years War, and Portugal, which had been dragged into conflict with Spain, found that its border defences were out of date. The government called in a foreign expert, the Count of Lippe, a German soldier of fortune and military reformer, who designed a new fortress on the highest hill overlooking the town. Work began in the 1760s and continued for decades, and the result was the most modern piece of the entire system, a fortress designed for the age of heavy artillery, with a star-shaped plan, deep ditches and underground galleries.
It is a big fort, with a large parade ground, a barracks, a chapel, powder stores and cisterns cut into the rock. The walls are lined with massive sloping banks to absorb cannon fire, and the tunnels let the garrison move without being seen. It was never put to the full test in a siege, but it has served in other ways, and in the twentieth century it also had a role as a prison. The UNESCO listing of 2012 includes it as one of the key elements of the Elvas system, a late example of the Dutch-style fortification that was the pride of the age.
From the walls you get the best view of the area: the old town below, the long line of the aqueduct crossing the plain, the other forts on their hills, and in the distance the Spanish plateau. On a clear day you can see for kilometres.
The road up is a short ride from the centre, a small winding lane with tight bends and a steep climb, so go carefully in the heat and watch for cyclists. Parking at the entrance is easy. Fuel and food are in Elvas, which is less than two kilometres away.
Check the opening times before you go, because access can vary, and guided visits may be needed. Spring and autumn are the best seasons, with soft light and green countryside. In high summer the stone becomes an oven. A nice detail: wild thyme and rosemary grow on the slopes, and their scent rises in the evening.