Twenty miles west out of Lisbon and well past the mouth of the River Tagus, this qualifies as the Atlantic Ocean.
The first thing you'll want to do, then, is bomb down to the beach and see what all the fuss is about. There is some beach down there but it's got rocks in it. Your best bet is the stretch behind you although it's a little too close to a railway line for SlyBob's liking.
It's likely you're already in Lisbon and doing a day trip? Just don't try asking for a ticket at the Cais do Sodré station for here... 'Kuzzsh-Kai-Eesh?' 'Cashh-Kay-oozzsh?' You're lucky, this was 2008 and them ticket machines are all automated now so you won't have to ask, probably.
Technically, this is a suburb of Lisbon but the municipality of Cascais is one of the wealthiest in Portugal. It's built up all the way in between so you could walk back there but more on that in a minute.
Cascais was once a simple fishing village and there's still a big old fish market down near the harbour making the local restaurants a draw if you're fond of the fin.
The heart of the old town has largely been modernised in what could be lazily described as a Mediterranean style and it's standard Euro-resort fayre in there. Yes, it's known this isn't on the Mediterranean but everyone's all been there so that's why it's so familiar.
Architecturally, they're all over the place... Gothic, Renaissance, Manueline and Pombaline, whatever they are. Most of it looks fairly new and faux, though, meaning the only crack you'll find is in O'Neill's Irish Pub.
 Advising trippers suggest the craic is 'mighty' although in SlyBob's experience it's often 'merely convivial'.
15th-century fortification that's down by the marina and you'll be doing well to miss it. There's a posh hotel in it now and the Portuguese President, whoever that is, is known to holiday here.
Following the road west along the sea front brings you to the Farol de Santa Marta or a lighthouse if you'd rather. Not just a lighthouse, a lighthouse museum that may or may not be as illuminating. Much more interesting were the surroundings, very concrete and precise, very white.
Carry on out for the Boca do Inferno, the Devil's Mouth, an eroded cliff formation that sees the Atlantic spewing up through a natural arch. Unless you're here in December in a howling gale, however, there's often not that much to see spewing-wise.
Aleister Crowley faked his own death there in 1930. Aleister Crowley? Only the Devil's mouthpiece.
Over 200,000 people call the Cascais 'area' home and that includes Estoril, which is the first place you'll meet legging it back to Lisbon. Developed as a 'luxury' resort although sitting at a table on Avenida Aida staring at a modern facade, you could, sorry Estoril, be just about anywhere.
Didn't they use to have the Portuguese Grand Prix here? They certainly did, about three miles north, but a reluctance to fill in some potholes put paid to that in 1997.
Isn't there a casino here? There certainly is, the largest in Europe, it's said, and the supposed inspiration for Casino Royale although it's not known if Fleming ever played the 'fruities' here himself.
Isn't there a train station here? There certainly is and any talk of walking back to Lisbon was just to emphasise the continuous conurbation along this coastline. The station's right behind you and with those return tickets in your back pocket, you won't have to ask for your destination...
'Kai-Eezzsh doo Shood-ray?' 'Kee-Aizzsh doo Zzoo-rah?'
Portuguese, the most unpronounceable of all the Romance languages, definitely.