Hidden between rock-strewn Unesco mountains, the bridge, called 516 Arouca, hangs 175 metres (575ft) above the fast-flowing River Paiva.
The attraction cost about 2.3million euros ($2.8 million/£2million) and took around two years to build.
The average person will take five to 10 minutes to complete the walk across the bridge, depending on nerves.
The landscape is calm, but the crossing is not for the faint-hearted.
Held up by steel cables and two massive towers on each side, it wobbles a little with every step.