From its striking hilltop position, Marialva's castle is visible from miles around. The 12th-century castelo is far from intact but it's still an impressive sight with its landmark keep, mighty walls and the remnants of a medieval village speckled with bushy olive trees.
You'll often have the castle almost entirely to yourself and can let your imagination go wild (careful: no railings and long drops should you peek too far over the edge).
Get tickets from the turismo near the chained entrance gate.
Marialva was originally inhabited by a tribe called the Aravos who built a hill fort here as defence against the Romans. However, much of the castle you see today dates to the 12th century when King Afonso Henriques had it built following Portuguese independence in 1179. Over subsequent centuries it was modified and added to, most notably by King Dinis who probably built the walls in the late 13th century.