About 15 minutes northeast of Porto de Mós by car (and signed from near the castle), a section of ancient Roman road has been converted into a walking trail. Marked with red and yellow blazes, the old road bed meanders through the hills for 9km; the most impressive section is the 100m bit at the signposted trailhead above the town of Alqueidão da Serra.
Estrada Romana
Estremadura & Ribatejo