Boca do Inferno (literally, "the mouth of hell") is the dramatic name given to a rocky archway and bay near Cascais, on the outskirts of Lisbon. The endless pounding of the ocean eventually hammered through part of the soft limestone cliffs that form the coastline in this part of Portugal, creating a cave which subsequently collapsed. The end result is an archway and small bay that's fully exposed to the ocean.
If you're there in summer, you'll likely wonder what all the fuss is about. Gentle swells lap quietly into the bay, and the endless sunshine reflects off the calm ocean. It feels like the perfect spot to take a few photos and admire the view, and about as far from the gates of hell as you can imagine.
Come back a few months later, however, and things will look very different. Fierce Atlantic storms batter the area, and it's easy to see how the spot got its name, as huge waves slam into the rocks and roar through the archway.
With the resulting spray often reaching higher than the surrounding cliffs, the spot has been a favorite for storm watchers for well over a century. Be careful visiting in particularly bad conditions, and always stick to the marked viewpoints and pathways. As impressive as the views are, the area can be dangerous, and both fishermen and tourists have died after falling from the cliffs there over the years.
The location of one of the first documentary films (in 1896), the Boca do Inferno shot to fame a few decades later when British occultist and magician Aleister Crowley faked his own death there, ostensibly after tiring of his then-girlfriend. He turned up alive and well at an exhibition in Berlin three weeks later, but the text of his "suicide note" is immortalized on a plaque at the site.
How Do I Get to the Boca Do Inferno?
A little over a mile west of the popular beachside town of Cascais, getting to the Boca do Inferno is straightforward. Most day visitors arrive by train from Lisbon, as there is a direct service from the downtown Cais do Sodre station, running every 20-30 minutes during daylight hours.
On sunny days, a popular approach is to walk or cycle along the coast from the train station or town center—just walk past the marina and lighthouse, and follow the road. It's also easily accessible by taxi or car. There is a reasonable amount of street parking available nearby, although it can get full at busy times.
The site is open year-round, and there's no fee to enter. Once you're there, you can view the Boca do Inferno from the top of the cliffs, or via pathways cut into the rock on either side. A few stalls sell some of the best-value souvenirs in the area, and there's also a cafe offering snacks and drinks onsite. Public toilets are available if you need them.
If you can manage it, time your visit around sunset for some spectacular photos, before walking back into Cascais. If you need them, trains back to Lisbon run until after midnight (pdf).
What Else is there to do Nearby?
Most visitors spend around half an hour at the Boca do Inferno.
Once you've had your fill of the crashing waves (or tranquility, depending on the time of year!), you have a few options for other places to visit in the area.
First off, there's Cascais itself. This former fishing village has transformed into a busy vacation spot for locals and tourists alike, although it still retains its laid-back seaside vibe. Three small beaches lie alongside the old town, and if they're too crowded for your liking, others lie within walking distance (or a short train or taxi ride) further east.
Cascais has plenty of excellent restaurants, not to mention some of the best gelato in the country, but if you'd prefer a high-end experience, take a taxi a few miles west to Praia do Guincho. This windswept stretch of sand is understandably popular with kitesurfers, who are easily visible from Fortaleza do Guincho, the Michelin-starred restaurant on the cliffs above the beach.
A few miles further afield lies Sintra, the former home of the Portuguese royal family, and one of the most popular day trips from Lisbon. It's possible to visit Cascais, Boca do Inferno, and Sintra in a single, very long day, but expect to be rushing from sight to sight from sunrise to sunset if you do!