Located about 1km from Cascais, it's an easy walk (there's a flat path that hugs the coastline all the way from the marina). Leading up to the Boca do Inferno, there are a series of cliff faces and rock formations being battered by waves, which give you a taste of what's to come.

The Boca do Inferno itself is one of those curious naturally formed rock formations that couldn't have been hand-sculpted any better. It's effectively a lagoon with almost vertical rock faces surrounding it, save for an archway (the boca/mouth) at one end. This acts as a funnel for huge waves to come crashing into the lagoon, which creates a swirl of white water. We were mesmerised for 15 minutes, waiting for the next big wave to come crashing in, while marvelling at the birds that would swoop through the archway and perch just out of reach from the incoming waves.

If you wanted to sum up the power of the ocean in one place, the Boca is a pretty good candidate.

This is an amazing formation and must be wonderful when the tide is high and the winds strong. Unfortunately when we visited all we saw were waves coming into to cove. Still an interesting spot with a good view of the cliffs rising out of the sea.

Actually, it's the cliffs nearby that I'm reviewing, the site itself is very cordoned off. This is a spectacular area, and well worth visiting. Very close by, there are amazing rocks to sit on and have a picnic. But, please, do not stand or sit on wet rocks. It may look peaceful enough work the odd high spray, but every 20 minutes or so there is a sudden almighty wave that is well and truly enough to wash someone away. The reason why the area is so-named.

I spent a couple of hours enjoying a picnic there before it got too stressful to watch...!