The Forte da Graça crowns a hill about a kilometre north of Elvas, designed in the 1760s as the outer keystone of the Elvas defensive system. It is a classic four-bastioned fort with a chapel and barracks inside the courtyard, and the views back across to the walled town and the Amoreira Aqueduct are the best in the area.
After decades of decay the fort was extensively restored and reopened to the public in 2015. Entry is ticketed and you can walk the ramparts and visit the interior galleries. Allow ninety minutes for the visit and another twenty for the drive up — the road is signposted from the centre of town.